CD274 and hereditary sensory and autonomic neuropathy: Furthermore, some research has indicated that high levels of PD-L1 expression may increase the risk of irAEs (80), and another study has identified a link between the occurrence of checkpoint inhibitor pneumonitis (CIP) and elevated PD-L1 expression (81).In a study focusing on immune-related adverse events in patients with gastrointestinal malignancies, it was found that patients with grade 3-5 irAEs exhibited significantly higher serum PD-L1 levels compared to those with grade 0-2 irAEs.