Here, we introduced the F311I/T315I compound mutation into the intrinsic BCR::ABL1 gene of a human TKI-sensitive Philadelphia chromosome-positive leukemia cell line via homologous recombination using the CRISPR/Cas9 system and obtained three types of sublines: the F311I mutation alone, the T315I mutation alone, and the F311I/T315I compound mutation. Here, BCR is linked to leukemia.