Macrophage-derived tumor necrosis factor and tumor-derived of leukemia inhibitory factor and interleukin-6: possible cellular mechanisms of cancer cachexia.

Background: The cellular basis for augmented cytokine production in the tumor-bearing host is not known. Recently leukemia inhibitory factor (LIF) and interleukin (IL)-6, produced by a variety of tumors, have been implicated as mediators of cachexia.