CD274 and yolk sac tumor: When we dichotomized PD-L1 expression on TILs, 37.0% of seminomas, 19.3 % of embryonal carcinomas and 19.2 % of yolk sac tumors had high PD-L1 expression (HS ≥ 160), while high PD-L1 expression on TILs was uncommon in teratomas (2.8%) and completely missing in choriocarcinomas (Table 3).