IL22 and multiple sclerosis: It is also been observed that Th‐17 cells migrate more effectively to the central nervous system (CNS) parenchyma in autoimmune disorders such as multiple sclerosis, due to their secretion of IL‐17 and IL‐22 which can disrupt the tight junctions of the BBB (Hirota et al., 2007; Okada & Khoury, 2012; Yamazaki et al., 2008).