We previously generated organoids from the antrum of patients with GC as described elsewhere [11,29,30] to treat them with various reagents, such as the rho-associated protein kinase inhibitor Y-27632, activin A, bone morphogenetic protein, glycogen synthase kinase-3 inhibitor CHIR99021, fibroblast growth factor 4, noggin, retinoic acid, and epidermal growth factor. The gene discussed is EGF; the disease is gastric cancer.