SSH1 and rheumatoid arthritis: NAV2 was first identified as an all-trans retinoic acid (atRA)-responsive gene in humans that is essential for normal development of the vertebrate nervous system.7 A previous study also clearly showed that NAV2 is overexpressed in human colorectal cancer (CRC) and plays a key role in promoting CRC cell invasion and metastasis by regulating F-actin polymerization via the SSH1L/Cofilin-1 pathway.8 However, the function of NAV2 in RA and relationship between NAV2 and RA pathogenesis remain unclear.