Specifically, tumor cells induced secretion of CCL2 (C-C motif chemokine ligand 2), leading to macrophage activation and subsequent TWEAK secretion by tumor cells via the CCL5/TRAF6 (TNF receptor-associated factor 6)/NF-κB signaling axis, which stimulated muscular atrophy [87]. The gene discussed is CCL2; the disease is neoplasm.