EGFR and acute myeloid leukemia: Lainey et al. [42] demonstrated that EGFR inhibitors, gefitinib and erlotinib alone did not promote differentiation but stimulated the acquisition of biochemical maturation markers and morphological change when combined with either ATRA or vitamin D. Lu et al. [43] demonstrated that trametinib, a highly selective inhibitor of MEK, enhanced ATRA-induced differentiation in AML cell lines U937, HL-60 and primary AML cells.