PDCD1 and neoplasm: When tumor samples were analyzed, several studies in melanoma and lung cancer and one study in kidney cancer have consistently linked higher TIL repertoire clonality with clinical benefit to anti-PD1/PD-L1 and/or CTLA-4;32,62,82, 83, 84, 85, 86, 87, 88 however, fewer and smaller studies in esophageal and mesothelioma reported the opposite trend (Figure 4A).89