MAP2K1 and acute myeloid leukemia: Two pieces of evidence suggest that MAPK regulation and C/EBPα-related effects in AML may be related: deletion of the MEK1-binding region of TRIB1 inhibits C/EBPα degradation [10,17,37], and C/EBPα degradation is inhibited by the MEK1 inhibitor U0126 [43,60].