CML-MSCs enhance immunosuppressive MDSCs production and aggregation, promoting tumor progression via upregulating immunomodulatory arginase-1 (Arg-1), IL-6, IL-1β, COX-2, and TNF-α in MDSCs and inhibiting anti-tumor immunity [40]. Here, ARG1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.