Any CML patient that does have a BCR-ABL over 1% and/or Ph* chromosome over 1% (absence of CCyR) after 18 months of TKI usage (particularly nilotinib and dasatinib) may be accepted as a failed case and the treatment strategy may be changed [15]. This evidence concerns the gene BCR and chronic myelogenous leukemia, BCR-ABL1 positive.