IL17A and systemic sclerosis: It has also been shown that SEMA4A-Plexin-D1 contributed to the elevated IL-4 and IL-17 in patients with systemic sclerosis (SSc), and the same manner can be seen for other T CD4+ mediate diseases, including asthma, rheumatoid arthritis (RA), and multiple sclerosis (MS) [[40], [41], [42]].