A substantial amount of research is currently focused on determining the mechanism behind cachexia development, with several factors considered to be putative mediators of cancer anorexia, including hormones (e.g. leptin), neuropeptides, cytokines (e.g. IL-1, IL-6, and TNF-α), and neurotransmitters (e.g. serotonin and dopamine). The gene discussed is LEP; the disease is cancer.