In both M-MDSCs and PMN-MDSCs, miR-30a is able to promote the expression of suppressive factors, such as arginase-1, IL-10, and ROS, by targeting SOCS3 and stimulating JAK2/STAT3 signaling, thus resulting in tumor growth, which correlates with increased levels of MDSC in the tumor microenvironment, and reduced CD8+ T-cell infiltration in tumors. The gene discussed is ARG1; the disease is neoplasm.