KMT2A and leukemia: Compound CCI-006 (Fig. 1a) demonstrated a selective cytotoxic effect against three out of four tested MLL-r leukemia cell lines, without significantly affecting the viability of MLL-wt leukemia (n = 6) and solid tumor (n = 4) cell lines, or noncancerous cells (n = 3) at 10 μM (Fig. 1b).