CD4 and multiple sclerosis: It has been reported that miR-140-5p was associated with many diseases such as cardiocerebral vascular diseases, tumors, autoimmune diseases, etc. Guan et al. (22) found that the expression of miR-140-5p was negatively correlated with multiple sclerosis, and miR-140-5p inhibited CD4+ T-cell differentiation and STAT1 activation, thus slowing the progression of multiple sclerosis.