Engineering Immune Organoids to Study Pediatric Cancer

This study collects tumor samples from children and young adults with cancer to build "immune organoids" — tiny lab-grown models of the immune system — to better understand how pediatric cancers interact with the immune system. **You may be eligible if...** - You are 25 or younger at the time of cancer diagnosis (no upper age limit for brain tumors or kidney tumors) - You have been diagnosed with or are suspected of having a brain tumor, kidney tumor, neuroblastoma, sarcoma, or related pediatric cancer **You may NOT be eligible if...** - You are an adult without one of the specific cancer types listed - You are unwilling to provide tissue samples Talk to your doctor to see if this trial is right for you.