DKK1 and psoriatic arthritis: Higher DKK1 level was found to be associated with higher disease severity (p < 0.001) as well as PsA Disease Activity Score (PASDAS) (p < 0.001), Simplified Psoriatic Arthritis Radiographic Score (SPARS) (p < 0.001) and PsA Impact of Disease (PsAID) (p = 0.001) [61].