In analyses of PsA patients compared to controls, we replicated the previously reported findings of prioritized genes (ICAM1, IRF1, STAT2, and TYK2) and target pathways (IFN and interleukin signaling) for psoriasis, further supporting the notion that psoriasis in patients with PsA is genetically and biologically similar to psoriasis in patients with PsC. This evidence concerns the gene IRF1 and pancreatic serous cystadenoma.