IL17A and inflammatory bowel disease: Although we did not see increases in the expression of any single marker (Extended Data Fig. 2a–d), we found an increase in IL-17A+FOXP3+ double-positive (DP) CD4 T cells in patients with PSC classified as I2, relative to patients with PSC classified as U (Fig. 3a) or patients with IBD classified as I2 (P = 0.024).