SYNCRIP and rheumatoid arthritis: In vitro experiments in cultured FLSs and further in vivo experiments using mouse models showed that LERFS negatively regulates RA FLS migration, invasion, and proliferation through interaction with hnRNPQ (heterogeneous nuclear ribonucleoprotein Q) and that this LERFS-hnRNPQ complex controls mRNA metabolism and cell motility by modulating the stability or translation of the RhoA, Rac1, and CDC42 mRNAs [30].