Inhibition of S1P1/3 has been shown to reduce the proliferation, migration, invasion, and pro-inflammatory cytokine release in MH7A cells, a human RA synovial cell line, whereas S1P2 suppression primarily affects cell invasion and the release of pro-inflammatory IL-1β and prostaglandin E2 [28]. This evidence concerns the gene S1PR1 and rheumatoid arthritis.