Measurement of the PACAP as well as other inflammatory substances, like PGE2 and PGI2, interleukin-6 (IL-6), tumor necrosis factor (TNF-α) and the c-Fos gene, all of which are typically upregulated in both clinical and preclinical migraine studies, have also been utilized (Han et al., 2017; De Logu et al., 2019). This evidence concerns the gene TNF and migraine disorder.