In the present study, we show that knockdown of AF1q by small interfering RNA (siRNA) suppresses cell survival and sensitizes CML cells or CD34+ CML progenitors to IM, whereas elevated AF1q expression contributes to cell growth and protection of CML cells from IM-induced apoptosis. This evidence concerns the gene MLLT11 and chronic myelogenous leukemia, BCR-ABL1 positive.