For example, the rag2 mutant line has been shown to be a useful model for human cancer xenotransplantation [32], while zebrafish prkdc mutants show 50–70% engraftment when injected intraperitoneally with tumor cells from human melanoma, leukemia, pancreatic cancer and bile duct cancer cell lines [33]. The gene discussed is PRKDC; the disease is neoplasm.