BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Although different reports have described the clinical history of CML patients displaying uncommon BCR-ABL1 transcripts (Gui et al., 2015; Ha et al., 2016; Cai et al., 2018; Chisti and Sanders, 2018; Qin et al., 2018), to date, the specific contribution of each different BCR and ABL1 domains modified in infrequent BCR-ABL1 fusions remain unclear.