Twenty-one CML patients resistant to TKIs were tested for BCR–ABL mutation; 9 of them were positive for Y253H (2); M244V (2); T315I (2); F317L (1); H396R (1) e G250E/Y253H (1) mutations. The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.