CD274 and cancer: Thus, exploiting the release by cancer cells into the blood of high amounts of PD-L1 (multiple myeloma, and hepatocellular carcinoma, among others 56, 57, Aghajani et al. recently detected a soluble form of PD-L1 (sPD-L1) in the serum (but not in plasma) from PTC patients but not in healthy controls 58.