CRH and rheumatoid arthritis: IPA analysis of the intronic and coding SNPs separately showed a total of 335 significant pathways in PDC80 intronic SNPs with the top three most significant pathways identified being the opioid signaling pathway, the endocannabinoid cancer inhibition pathway, and the corticotropin releasing hormone signaling pathway, while only one significant pathway was seen with the PDC80 coding SNPs, the role of chondrocytes in rheumatoid arthritis signaling pathway (Table S1).