PDCD1 and neoplasm: The search was performed using various combinations of keywords and Medical Subject Headings (MeSH) terms, including but not limited to "immune checkpoint inhibitors," "cancer," "neoplasms," "pancreatitis," "CTLA-4," "PD-1," "PD-L1," "ipilimumab," "nivolumab," "pembrolizumab," and "adverse events."