It is known that PD-L1 in many tumors has high expression, including lung cancer, colorectal cancer, gastric cancer, melanoma, leukemia, stromal tumor, multiple myeloma, esophageal, ovarian, pancreatic, renal cell carcinoma, oral squamous cell carcinoma, and nasopharyngeal carcinoma [11–18]. Here, CD274 is linked to plasma cell myeloma.