Therole and alteration in the level of SEMA3A have beeninvestigated in some autoimmune diseases, includingsystemic lupus erythematosus (SLE), rheumatoidarthritis (RA), psoriasis and systemic sclerosis (SSc).In some of these studies, down-regulation of SEMA3Ahave been reported (7, 23-25). This evidence concerns the gene SEMA3A and psoriasis.