CDK4 and leukemia: The observed effects of the combination on KMT2A-r leukemia cell survival were associated with downregulated expression of genes involved in proliferation and cell cycle progression including MKI67, CCNB1, CENPV, CDK4 and cMYC in infant KMT2A-r leukemia cells PER-485, PER-703 and PER-494 (Figure 2D).