Involved in the negative regulation of lymphocyte motility. It mediates the migration-inhibitory effects of IL6. Serves as a positive regulator of the RhoA signaling pathway. Enhancement of RhoA activation results in inhibition of lymphocyte and lymphoma cell motility by activation of its downstream effector ROCK. Is a regulator of B-cell receptor signaling, that acts through SYK kinase activation. {ECO:0000269|PubMed:17823310, ECO:0000269|PubMed:20844236, ECO:0000269|PubMed:23299888}. This is the function of ENSG00000174500 (GCSAM, germinal center associated signaling and motility).