Although the success of TKIs in CML is tremendous, 20%–25% of CML patients undergoing TKI therapy develop resistances within 5-years of treatment resulting in relapses (Milojkovic and Apperley, 2009; Hochhaus et al., 2017) resulting in the development of novel BCR::ABL1 TKIs. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.