Oliver – The Ninja’s Team

by | Aug 11, 2025

Oliver Team Ninja Logo

Contact: Ashley Rentmeester
Email: [email protected]
Location: Eldridge, Iowa

Oliver's Story

  We are Jared and Ashley Rentmeester and along with our daughter Eliza, would like to tell you about Oliver.

Oliver was our best boy. He was a bright five-year-old. He was a thinker and a doer. He asked complex questions and was a creative problem solver. Oliver was proud of how smart he was and one Thanksgiving he listed his big brain on his list of things he was grateful for. Even as a toddler, Oliver worked as he played. He would build, paint and haul. He was great at helping with chores inside and outside. He wanted to be a farmer when he grew up. He had a tender heart and fiercely looked out for his sister. He was a helpful neighbor and classmate. He was always asking, “Can I help? Do you have a job for me?” He had a beautiful gap tooth smile, and the best giggle.

Oliver loved math/numbers, asking questions, Legos, puzzles, holiday yard blow ups, tractors, his Power Wheels Jeep, T-Rexes, school, Mac and cheese, chicken nuggets, Rice Krispie Treats, sugar cookies, sprinkle doughnuts, sleeping with his hand behind his head, the color green, and Hulk.

In January of 2023 Oliver started having intense headaches. We were working to find an answer. On March 1st Oliver said he didn’t feel good, could not focus with his eyes and his left leg/ foot were not working properly. The local ER did a scan and found a mass in his brain. We were taken by helicopter to University of Iowa’s Stead Family Children’s hospital. During his time in the PICU (Pediatric Intensive Care Unit) Oliver had to have frequent neurological checks as he waited for surgery. The staff would comment on how strong he was. He would proudly say, “That’s because I’m a ninja!” He had been taking classes at a local gym. His coaches stopped by with a ninja picture for him to color. One of the nurses took it and made copies. Soon Oliver was getting stacks of well wishes from the hospital staff, which then continued with more from our community. From then on he was Ninja Oliver.

A few days later he had the orange sized tumor removed from his brain. We were given the diagnosis of AT/RT (Atypical teratoid rhabdoid tumor), a rare and aggressive neurological cancer. Oliver went through 2 rounds of intensive chemo. At the end of May it was decided we needed to switch to radiation treatment because he still had cancer cells in his spinal fluid. We went to Mayo for 6 weeks and then spent the rest of the summer at home. In August he was able to start Kindergarten. He attended 3 days in person and then virtually because he started with 2 more rounds of chemo. October 13th he was inpatient at the hospital and started vomiting a lot and was doing some odd rocking. A nurse pushed for an MRI. We found out his cancer was actively growing. This time it was not a tumor, but wisps and we were told it was not curable. We made plans to try to slow its growth and went home for about 24 hours before he pretty much went unresponsive. He passed away after his courageous 237 day journey on October 23, 2023 at 7 pm.

You can learn more about Oliver’s journey and how we continue to honor his memory on Caring Bridge.

https://www.caringbridge.org/site/0b6ffd08-f0d2-37c0-84c0-970d782428e9

What do you want people to know about pediatric cancer?
Pediatric cancer changes your whole life in an instant. It breaks your heart in so many ways. Seeing your child in pain, not feeling well and scared is horrible. The mental, physical and emotional toll it takes on the parents and families is utterly exhausting. The worry is constant. Unfortunately, cancer took our boy. It is now our mission to continue to tell his story.

Being in this horrible club has brought us into contact with some very amazing people. We met so many wonderful staff at University of Iowa and Mayo. We are grateful for all they did to help Oliver fight and the support they gave to our family. We have met and gotten to know so many amazing families who have also faced pediatric cancer.

Why are you part of The High Hopes Initiative?
We are so happy to be part of the High Hopes Initiative and the Rally for Reid Foundation. We have amazing family, friends and community that have supported us through Oliver’s illness as well as since his passing. People have been so supportive and generous. We found The High Hopes Initiative as the best way to honor Oliver’s memory with the support of the Rally for Reid Foundation and we are grateful for this opportunity.

Oliver spent about 100 days inpatient at Stead Family Children’s Hospital. During those stays we were supported with daily meal vouchers supplied by the Rally for Reid Foundation. This was a great help to our family. It also became a fun game to see how much food we could get with the voucher and several times we hit the total exactly! It’s the little things you do to keep your mind occupied when your child is inpatient. We would like to help other families by supporting this program.

The Foundation and Reid’s mom, Megan, have supported us more personally near Oliver’s end of life and especially after Oliver’s passing. We were given a couple of truly special items to help honor his memory. The support from other families who have faced similar situations is comforting, and we do our best to help other families as well. Oliver was always a helper, so in helping others we are also honoring who he was and how he lived.

We believe in supporting the need for pediatric cancer research, especially for brain tumors. Throughout Oliver’s treatment and after he passed we donated his tissue to be researched. While progress has been made it is not nearly enough.

What are your favorite events or things to do to honor your child?
We do our best to honor Oliver everyday. We talk about him often. We reminisce about memories and notice things around us that remind us of him. We still share pictures and videos of him on Facebook.

Oliver passed away exactly six weeks before his 6th birthday. Oliver really wanted to turn 6. To remember and honor Oliver on his birthday, December 4th, we have collected toys, electronics and personal hygiene items. With the help of our community we have taken over 1,600 items to the University of Iowa Stead Family Children’s Hospital in just 2 years.

We also hold a blood drive on his birthday. Blood products are so crucial to cancer patients and we saw firsthand how blood products positively impacted Oliver’s well being during treatment. The community is so wonderful and over 500 donations of blood products have been made in Oliver’s name through ImpactLife.

We have been a part of University of Iowa’s Dance Marathon where we have been able to speak about Oliver and share his story. This past school year, North Scott schools started their Mini Dance Marathon after a five year break from holding the event. It is important to spread awareness about pediatric cancer.

When Oliver was in the hospital and everyday for his 30 days of radiation he had a treat bucket. He would offer a treat to anyone who came into his room. He would go on wagon rides or walks and pass out treats. Oliver loved to help others so this was a way that we could say thank you and support the hospital staff. We still supply treats for the staff several times a year.

Support Our Cause

We do our best to honor Oliver’s memory by making a difference in this world and we appreciate your support in helping us do that.