RAG2 and acute lymphoblastic leukemia: To determine the anti-T-ALL activity of S63845 and venetoclax, we harvested green fluorescent protein (GFP)-labeled zebrafish T-ALL cells from 3-month-old Tg(rag2:Myc; rag2:EGFP) transgenic zebrafish [14], and intravenously injected these T-ALL cells into 2-day-old zebrafish embryos [15].