CD274 and neoplasm: After the combination therapy of pembrolizumab and metronomic cyclophosphamide, the increased infiltration of IDO+ M2 failed the therapy because tumor shrinkage was observed in just 3 of the patients with only one experiencing partial response when the total number was 57 and over 40% patients expressed PDL1 in the TME (Toulmonde et al., 2018).