CD274 and Keratoconjunctivitis sicca: In the KEYNOTE-010 clinical trial, which compared pembrolizumab to docetaxel for previously treated, PD-L1-positive, advanced non-small-cell lung cancer, out of 1,034 study subjects, ten (1.5%) treated with pembrolizumab experienced grade 1, 2 dry eye, while only one person treated with docetaxel reported dry eye (Herbst et al., 2016).