PDCD1 and hereditary clear cell renal cell carcinoma: In renal cell carcinoma (RCC), immunohistochemistry and flow cytometry experiments to evaluate TIGIT and PD-1 expression in circulating immune cells and TILs revealed an increased TIGIT and PD-1 expression in the tumoral area compared with adjacent normal tissue, but TIGIT+ T cells and NK cells amount did not correlate with clinicopathological characteristics (age, sex, tumor diameter, Fuhrman grade, or TNM stage) (162).