Our findings confirmed expression of NKL family members in T-ALL cell lines, namely: TLX1 in ALL-SIL, TLX3 in HPB-ALL, NKX2-5 in PEER and CCRF-CEM, and NKX3-1 in JURKAT, PER-117 and RPMI-8402 (data not shown). This evidence concerns the gene TLX1 and acute lymphoblastic leukemia.