CSH1 and inflammatory bowel disease: To address this question directly, we exposed healthy and IBD Chips lined by cells from female patients to estrogen (E2) and medroxyprogesterone acetate (MPA) to recapitulate the menstrual cycle or a mixture of pregnancy-associated hormones (E2, MPA, human chorionic gonadotropin, prolactin, and placental lactogen) to mimic the first trimester of pregnancy.