Embryonal Tumor With Multilayered Rosettes

This study is researching a very rare and aggressive childhood brain tumor called ETMR (Embryonal Tumor with Multilayered Rosettes). It aims to collect data and tissue samples to better understand and treat this cancer. **You may be eligible if...** - You (or your child) have a confirmed diagnosis of ETMR, either by molecular testing or by looking at tissue under a microscope - There is enough tumor tissue available (at least 10–20 slides or a tissue block) for analysis - Depending on the treatment group (cohort), you may or may not have received prior cancer treatment **You may NOT be eligible if...** - There is not enough tumor tissue available for testing - The study chairs have not approved enrollment based on your specific situation Talk to your doctor to see if this trial is right for you.