ABL1 and acute lymphoblastic leukemia: It was thus hypothesized that TKIs specific to ABL1 (e.g., imatinib) or JAK (e.g., ruxolitinib) might be valuable options also for BCR-ABL1 like ALL cases of the ABL-class or JAK-class respectively (Boer et al., 2017; Fazio et al., 2020), and might represent a better therapeutic choice for these patients, who respond poorly to conventional chemotherapy (Den Boer et al., 2009; Roberts et al., 2012; Boer et al., 2015).