TNF and lung cancer: Furthermore, Hsp70/90-expressing exosomes could also bind and activate TLR2/TLR4 on the surface of immune cells, triggering the innate immune response and systemic inflammation in lung cancer-bearing mice, thereby inducing the synthesis and secretion of pro-inflammatory factors IL-6 and tumor necrosis factor-alpha (TNF-α), eventually stimulating skeletal muscle degradation [99].