LILRB4 and plasma cell myeloma: LILRB4 was expressed in 50% multiple myeloma (17/34) (Fig. 1A), 8% prostate cancer (4/50) (Supplementary Fig. S1A), 4.5% hepatocellular carcinoma (5/110) (Supplementary Fig. S1B) and 11.9% melanoma (10/84) (Supplementary Fig. S1C).