CD274 and yolk sac tumor: PD-L1 positive TILs were found significantly more often in seminomas (95.9% of all 225 patients with TILs) and embryonal carcinomas (91.0%) compared to yolk sac tumors (60.0%), choriocarcinomas (54.5%), teratomas (35.7%) or germ cell neoplasia in situ (GCNIS) (80.6%) (All p < 0.05).