MHC-II and CIITA downregulation occurs independent of BCR-ABL kinase activity in CML stem/progenitor cells. Primary (A) CD34⁺CD38⁺ CML cells and (B) CD34⁺CD38⁻ CML LSCs were cultured for 48 hours with TKIs (5 µM NIL, 150 nM dasatinib, 5 µM IM) or no drug control (NDC) in the presence or absence of IFN-γ. Average normalized MFI of MHC-II expression was determined using flow cytometry (n = 5; ± SEM). (C) CIITA expression levels in CD34⁺CD38⁺ CML cells were analyzed by quantitative reverse transcription polymerase chain reaction (n = 5; ± SEM; calibrated to UT NDC sample). Statistical significance was calculated between UT CML sample and all other samples and, if significant, is indicated by asterisks above the bars.