In sensitivity analyses, the observed increase in risk of melanoma among PDE5 inhibitor users was of similar magnitude to that estimated in the main analysis when the analysis was restricted to those diagnosed with diabetes prior to index date (HR = 1.11, 95% CI 0.81–1.52, p = 0.51) and when the first year after the index date was excluded from analysis (HR = 1.13, 95% CI 0.99–1.29, p = 0.07), though—as expected due to the reduced numbers—confidence intervals were wider. The gene discussed is PDE5A; the disease is diabetes mellitus.