FEN1 and psoriatic arthritis: Lauwerys et al. (2015) additionally compared gene expression from the same generated SLE dataset to RA, OA, psoriatic arthritis, and microcrystalline arthritis synovial gene profiles in which type I interferon-induced genes IFI27, ISG15, RAD2, IFI6, IFIT3, and OAS1 were among the top 100 discriminant genes defining SLE between the 5 arthritides15.