To evaluate the biological role of KLC2 mutants (MT) in CML cells, we expressed KLC2-MT in different human CML cell lines harboring BCR::ABL1 and performed immunoblot, immunofluorescence, cell proliferation, differentiation, and apoptosis; Tyrosine kinase inhibitor (TKI)-drug activities; and clonogenic assays for in vitro functional analyses. The gene discussed is KLC2; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.