Unlike BCR::ABL1/JAK2 double-positive cases, the majority of cases carrying the CALR mutation and BCR::ABL1 rearrangement fell into the group of CML preceding Ph-negative MPN (54.16%), followed by Ph-negative MPN preceding CML (37.5%) and, finally, by concomitant CML and Ph-negative MPN (8.33%). The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.