TNF and inflammatory bowel disease: Several chronic inflammatory disorders, such as rheumatoid arthritis, and inflammatory bowel diseases, present a reduced vagal-parasympathetic activation of the sympathovagal balance, and, due to chronic inflammation (persistent and unregulated TNF-α levels), there is a significant amount of chronic tissue damage, which is the driver for the pathogenesis of these conditions (Bonaz et al., 2016; Kalliolias and Ivashkiv, 2016; Koopman et al., 2016; Tsaava et al., 2020).