IFNA1 and chronic myelogenous leukemia, BCR-ABL1 positive: The beginning of the use of INF as treatment for CML started at 1983 after a report by Talpaz et al that leukocyte IFN induced cytoreduction in CML.1 Other studies confirmed the effect of IFN in CML.2,3,5 Complete hematologic responses were observed in 80% of CML patients treated with IFN and in 7–10% of them complete cytogenetic responses (CCyR) were obtained.