PDCD1 and pneumonitis: When stratified according to the treatment regimen, anti-PD1 treatment was complicated more frequently with immune-related arthritis, pneumonitis, myocarditis, thyroiditis and hematologic toxicities, whereas anti-CTLA4-driven toxicities included colitis, hypophysitis and skin rash; types of toxicities and kinetics according to treatment are summarized in Figure 2.