In this work, we aimed to characterize the biochemical effects of the frequent somatic missense cancer mutation in NSD2 (T1150A) and its NSD1 analog (T2029A) both observed in leukemia in addition to three other somatic cancer mutations in NSD1 observed mostly in solid cancers (Y1971C, R2017Q and R2017L). The gene discussed is NSD2; the disease is leukemia.