MAP2K1 and acute lymphoblastic leukemia: As shown in Figure 1A, pevonedistat significantly increased the cellular levels of p-PKCα/β II (Thr638/Thr641) and phosphorylated Ca2+/calmodulin-dependent protein kinase II (p-CaMKII) in all three ALL cell lines examined, which correlated with p-MEK1/2 (Ser217/Ser221) and p-ERK1/2 (Thr202/Tyr204) activation (Figure 1A).