ATF4 and acute myeloid leukemia: Further studies have also shown that in daunorubicin resistant AML cell lines, ATF4 binding is enriched at a stress-responsive enhancer for the ABCB1 gene which encodes the p-glycoprotein drug efflux pump implicated in multi-drug resistance; thus, indicating a potential role for ATF4 in mediating drug-resistance in AML [60].