Nishino et al. compared the incidence of pneumonitis in association with PD-1 inhibitor use across different tumor types and reported that the incidence in non-small cell lung cancer was significantly higher in both all-grade (4.1% vs. 1.6%; p = 0.002) and ≥ grade 3 (1.8% vs. 0.2%; p < 0.001) diseases than in melanoma [14]. The gene discussed is PDCD1; the disease is melanoma.