Kupffer cells are macrophages that reside within hepatic sinusoids. They are indirectly involved in fibrogenesis because they generate cytokines (ie, _____) to assist in the activation of stellate cells; however, their primary function is bacterial phagocytosis and the clearance of red blood cells?
1) Interleukin-1 (IL-1)
2) Interleukin-6 (IL-6)
3) Tumor necrosis factor-alpha (TNF-alpha)
4) Interferon-gamma (IFN-gamma)