MAPK1 and neoplasm: The MSK1 regulation of tumor dormancy via p38 is associated with the basic helix-loop-helix family member e41 (BHLHE41/DEC2) [43], the orphan nuclear receptor 1 (NR2F1) [44,45], BHLHB3 and p53 [46], and the downregulation of c-Jun and forkhead box protein M1 (FoxM1) [46] through p21 and p27 induction to tighten the inhibition of the cyclin-CDK complex [47].