IL23R and psoriatic arthritis: For the IL23R SNP there was significant association in the psoriatic arthritis subtype (P trend = 0.04, OR = 0.4 95% CI 0.16 to 0.98) and a trend towards association in the enthesitis related subtype (P trend = 0.15, OR = 0.52 95% CI 0.21 to 1.28).