NRAS and leukemia: As shown in Figure 6A, ABCB1 and three other ABC transporters (ABCA1, CFTR and ABCG2) have a relatively low mutational frequency in AMLs (1/144 or 0.69%) compared to other frequently mutated genes in leukemias (e.g., NRAS, KRAS, PTPN11, NPM1, FLT3, DNMT3A and IDH2), which have an average simple somatic mutation (SSM) frequency of 10.1% [Figure 6A].