To evaluate the in vivo immunomodulatory activity of the crude polysaccharide from Helicteres angustifolia L. (HACP), a 4T1 breast tumor model in BALB/c mice was used in this study. After tumor incubation for 6 days, mice were orally administered with 100, 200, and 300 mg/kg of HACP for 15 days. The