According to a retrospective analysis using the FDA Adverse Event Reporting System (FAERS), the frequency of ICI-induced hypophysitis varied by treatment type: 0.80% for PD-1 inhibitors, 0.47% for PD-L1 inhibitors, 1.79% for CTLA-4 inhibitors, and 4.06% for combination therapy (PD-1/PD-L1 + CTLA-4 inhibitors). This evidence concerns the gene CTLA4 and hypophysitis.