In which of the following organs are Kupffer's cells present?

Kupffer cells are resident macrophages of the liver. They are located within the lumen of the sinusoids overlapping the thinned endothelial wall. Kupffer cells represents the largest population of macrophages in the mammalian body and are largely responsible for clearing the post mesenteric blood of gut derived bacteria and potent bacterial toxins such as endotoxins or peptidoglycans. Morphologically they are different from other macrophages as they show a characteristic pattern of endogenous peroxidase staining of the rough endoplasmic reticulum and perinuclear envelope. They express CD68 antigen and they also possess cell specific antigens eg: glucose/fructose receptor. Ref: Cooperation of Liver Cells in Health and Disease: With 18 Tables By Zbigniew Kmie? page 21.