PDCD1 and pneumonitis: Serial Interferon-gamma (IFN-γ) release assessed by enzyme-linked immunosorbent assay in NSCLC treated with PD-1 or PD-L1 inhibitors showed that patients with <10 IU/ml at baseline or immediately after the first dose of ICI (2-4 weeks) had more lung-irAE (pneumonitis) risk (103).