These genetic events mark distinct subgroups, i.e., TAL/LMO, HOXA, TLX3, TLX1, NKX2-1/2-2, MEF2C, allowing the molecular classification of at least 70% of T-ALL cases, with different distribution in children and adults (Figure 2) [5,6,7,8,9]. Here, TLX1 is linked to acute lymphoblastic leukemia.