TLR4 and neoplasm: In the present study, we first investigated the immunomodulatory activity of PSP in peritoneal macrophages from C57BL/10J (TLR4+/+) and C57BL/10ScCr (TLR4-/-) mice carrying a defective toll-like receptor-4 (TLR4) gene and then evaluated PSP for its effect on tumor inhibition rates and the immune organ index in above two different strains of mice.