CD274 and small cell lung carcinoma: TEX-bound PD-L1 are also being explored as biomarkers in NSCLC, small cell lung cancers, gastric cancer, HNSCC, CRC, RCC, hepatocellular carcinoma, esophageal carcinoma, and melanoma, and results to date have shown that exosomal-PD-L1 was (i) significantly higher before treatment in the plasma of non-responding patients; and (ii) decreased during therapy, and this decrease is associated with a decreased tumor burden [68].