4,4'-Dimethoxybenzil is a human intestinal carboxyl esterase (hiCE) inhibitor with K_i of 70 nM. IC50 & Target: Ki: 70 nM (hiCE)^[1] In Vitro: By reducing irinotecaninduced diarrhea, hiCE inhibitors (e.g., 4,4'-Dimethoxybenzil, Compound 8) can improve the anti-cancer efficacy of irinotecan. To find effective hiCE inhibitors, a new virtual screening protocol that combines pharmacophore models derived from the hiCE structure and its ligands has been proposed^[1].