SOCS3MyeKO bone marrow cells preferentially differentiated into MDSC-like cells when cultured in conditioned medium from TRAMP-C1 prostate cancer cells, and TRAMP-C1 tumor growth was accelerated in SOCS3MyeKO compared to WT mice, indicating that SOCS3 can control the extent of MDSC production and may indirectly regulate NK activity in the tumor microenvironment. The gene discussed is SOCS3; the disease is neoplasm.