For biopsy samples taken in endoscopically affected areas, IL8 was increased by as much as 38-fold in UC (p<0.0001) (Fig. 1A), 35-fold in colonic CD (p<0.0001) (Fig. 1A) and 35-fold in ileal CD (p = 0.001) (Fig. 1B) when compared to healthy controls. Here, CXCL8 is linked to Cowden disease.