In anti-PD-1 monotherapy group, melanoma patients experienced the most frequent fatigue (31.1 %, 95 % CI 29.7%–32.5 %); the incidences of severe pneumonitis and other respiratory disorders were highest in Hodgkin lymphoma (4.1 %, 95 % CI 1.5%–8.6 %; 4.1 %, 95 % CI 1.5%–8.6 %, respectively). Here, PDCD1 is linked to respiratory system disorder.