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. Interacts with ACTB and MYH2; the interaction with MYH2 is increased by IL6-induced phosphorylation. Interacts (via C-terminus) with ARHGEF11 (via DH domain). Interacts with ARHGEF12. Interacts with SYK; the interaction increases after B-cell receptor stimulation, resulting in enhanced SYK autophosphorylation and activity. It relocalizes from the cytoplasm to podosome-like structures upon cell treatment with IL6. Expressed in diffuse large B-cell lymphoma (DLBCL) and several germinal center (GC)-like lymphoma cell lines (at protein level). Highly expressed in normal GC lymphocytes and GC-derived malignancies. Expressed in thymus and spleen. Up-regulated by IL4/interleukin-4. Phosphorylation on tyrosine residues can be induced by IL6. Phosphorylation is mediated by LYN.