ET140203 T Cells in Pediatric Subjects With Hepatoblastoma, HCN-NOS, or Hepatocellular Carcinoma

This study is testing a new type of cell therapy — specially engineered immune cells (T cells) called ET140203 — to treat children and young adults with liver cancers (hepatoblastoma or hepatocellular carcinoma) that have come back or stopped responding to standard treatment. These modified T cells are designed to recognize and attack liver cancer cells. **You may be eligible if...** - You are between 1 and 21 years old - You have been diagnosed with hepatoblastoma (HB), hepatocellular carcinoma (HCC), or a related liver cancer - Your cancer has relapsed or did not respond to standard treatment - Your blood AFP level (a liver cancer marker) is above 100 ng/mL - You carry a specific genetic marker (HLA-A2) that allows the therapy to work - Your liver function and overall health meet minimum requirements **You may NOT be eligible if...** - Your cancer can be completely removed by surgery - You have a serious uncontrolled infection or heart/lung condition - You have very poor liver function Talk to your doctor to see if this trial is right for you.