KMT2A-knockdown in U87MG cells transplanted into 2 dpf Tg(fli1:EGFP) zebrafish brains increased both tumor growth and angiogenesis, even when embryos were treated with an immune suppressant (dexamethasone), revealing that KMT2A acts negatively on tumor growth in contrast with the previous conception of KMT2A as an oncogene in tumorigenesis [162]. The gene discussed is FLI1; the disease is neoplasm.