Conversely, Cooper et al., using immunohistochemistry (Merck; clone 22C3) and considering a 50% expression threshold as indicative of high expression, found in a study of 678 stages I-III NSCLC patients that high PD-L1 expression appears to be a favorable prognostic factor in early-stage disease20. The gene discussed is CD274; the disease is non-small cell lung carcinoma.