IFNA1 and chronic myelogenous leukemia, BCR-ABL1 positive: In a study by Mahon et al. IFNα treated CML patients who were in CCyR or bcr-abl negativity, discontinued IFN and 8 patients lost CCyR after 3–33 months.11 Seven patients that were in CCyR>24 months and were bcr-abl negative before discontinuation did not relapse (median time of observation 36 months).