IFNA1 and chronic myelogenous leukemia, BCR-ABL1 positive: Reasons for these different findings between the French SPIRIT trial and the Nordic trial on one side and the German CML Study IV and the MDAnderson trial on the other side are not clear at the moment; however, multiple differences present in the protocols (i.e., the type of IFN used, patient populations, and trial designs) need to be considered.