PDCD1 and cancer: In the present study, we aimed to identify potential predictors of irAEs by investigating related factors such as peripheral blood biomarkers, medical records, and liquid biopsy results in real-world cancer patients receiving anti-PD-1/PD-1 ligand (PD-L1) therapy, and to evaluate the relationship between irAEs and the clinical efficacy of anti-PD-1/PD-L1 inhibitors.