TNF and neoplasm: The major influence of the tumor on the macroenvironment appears to be related to excess of cytokines in the serum: (1) many tumors secrete pro-inflammatory factors (eg, tumor necrosis factor alpha [TNFα], IL-6) and pro-catabolic factors (eg, zinc α2-glycoprotein [ZAG]); and (2) factors released by the host as a response (eg, interferon gamma [IFNγ] and ZAG),61 which are responsible for promoting degradative pathways in skeletal muscle and adipose tissue.