TNF and psoriasis: The serum level of TNFα in healthy individuals is ~3.21 ± 4.04 pg/mL [28], and altered levels of TNFα have been linked with several diseases and conditions, including autoimmune diseases such as chronic inflammatory bowel diseases (Crohn’s disease) [36], rheumatoid arthritis [20,37], ankylosing spondylitis [38] and psoriasis [39], and cancers [40].