ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: However, studies show a conflicting role in CML, as upregulation of OCT1, as well as an absence of OCT1 expression in imatinib and nilotinib resistance, but also other BCR::ABL1 TKIs was demonstrated (White et al., 2007; Nies et al., 2014; Kumar et al., 2022).