ARG1 and chronic myelogenous leukemia, BCR-ABL1 positive: The increased upregulation of immunomodulatory factors, such as TGF-β, IL6, and IL-10, in CML-derived MSCs, correlates with their capacity to promote PMN-MDSC generation and cell reprogramming, which occurs in conjunction with their increased expression of immunosuppressor enzymes, such as ARG1 and COX-2.