Studies performed in patients with intrahepatic cholangiocarcinoma and nasopharyngeal carcinoma reported lower overall survival and a higher recurrence rate [27, 74], while studies performed in patients with HGSOC and NSCLC reported a positive correlation between the presence of PD-1+ TILs and disease-specific survival and OS respectively [75, 76]. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.