IL17A and psoriasis: As such, IL22 correlated with several genes that did not appear to have a relationship with IL17A. In addition, a set of genes identified to be involved in psoriasis pathophysiology (CARD14, CXCL5, CXCR2, DDX58, IFIH, PTPN22, and TNFRSF9) correlated with IL17A and IL23A, but did not correlate with IL22.