Knockout/overexpression of KAT8 correlated positively with phosphorylation of serine 139 in H2A.X variant histone (H2AX), a DNA damage marker (γH2AX), in MLL-AF9 leukemia cells, indicating that KAT8 promotes DNA damage repair and inhibits apoptosis in AF9 cells [64]. Here, H2AX is linked to leukemia.