Furthermore, a population of CCR6+CCR4-CXCR3+ Th1/Th17 cells has been described which express both T-bet and RORγ, produce IL-17 and IFN-γ, and may play a pathogenic role in IBD.31–35 Increased Th17 responses are found in IBD and have also been associated with liver inflammation and PSC.19,36 The frequency of circulating CCR6+CCR4+CXCR3- Th17 cells was higher in both patients with PSC-UC and those with UC only compared with controls, whereas no differences were observed in the Th1/Th17 subset. Here, IL17A is linked to inflammatory bowel disease.