Tarafdar et al. have demonstrated that IFN-γ treatment of CML stem/progenitor cells induced the re-expression of MHC-II antigens, that were down-regulated by JAK1/2-mediated signals from either CML cells and/or by the CML-modified microenvironment. The gene discussed is JAK1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.