SOCS1 and plasma cell myeloma: Due to the ability of SOCS1 to inhibit various signaling pathways in tumor cells, the decreased expression of SOCS1 in cancer may represent a diagnostic and prognostic biomarker of clinical outcome in patients with myeloma, breast cancer, hepatocellular carcinoma, melanoma, or neuroendocrine tumor, suggesting SOCS1 may be a potential target for antitumor therapy [14, 15, 50-52].