A secondary analysis of the phase I KEYNOTE-001 trial (ID: NCT01295827) demonstrated that the PD-1 inhibitor pembrolizumab markedly enhanced OS in NSCLC patients with previous RT exposure, in contrast to those without, yielding a median OS of 10.7 months versus 5.3 months (p = 0.034) [91]. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.