A genome-wide association study with CD patients showed a high association of IL-23R and CCR6 to states of active disease, while another study indicated that patients with active disease had higher numbers of IL-17 and IL-23p19+ cells in the lamina propria and had increased mRNA expression of IL-17, IL-6, IL-23, IL-1β, and CCR6 [185–188]. Here, IL17A is linked to Cowden disease.