Notably, a recent in vitro study that exposed human brain microvascular endothelial cells (BMECs) to serum from patients with relapse-remitting MS (RRMS) found that serum from patients with RRMS lowered claudin-5, an integral TJ protein expression, and decreased transendothelial electrical resistance [65]. The gene discussed is CLDN5; the disease is relapsing-remitting multiple sclerosis.