Furthermore, CML patients with the CC genotype of ABCG2 rs2231142 had a six-fold higher risk (95% CI 1.445–27.410, p < 0.014) of developing TKI resistance and five times less time before a second line of treatment (HR = 5.396, 95%CI 1.310–22.240, p = 0.020) in comparison with A-allele carriers (Figure 2b). This evidence concerns the gene ABCG2 and chronic myelogenous leukemia, BCR-ABL1 positive.