RAC1 and ankylosing spondylitis: However, Rac1 seems to be an important player concerning OPC migration, which could also be confirmed in a model of Ankylosing spondylitis (AS) (Xiao et al., 2013; Cui et al., 2022) and so we conclude that inhibition of RhoA released Rac1 from blockage by RhoA and therefore intensified the motility of OPCs.