Regulates G protein-coupled receptor signaling cascades, including signaling downstream of the N-formylpeptide chemoattractant receptors and leukotriene receptors (PubMed:10480894). Inhibits B cell chemotaxis toward CXCL12 (By similarity). Inhibits signal transduction by increasing the GTPase activity of G protein alpha subunits thereby driving them into their inactive GDP-bound form (PubMed:10480894, PubMed:18434541). Interacts with GNAI1 and GNAQ. Detected in peripheral blood monocytes (PubMed:10480894). Expression is relatively low in B-cells and chronic lymphocytic leukemia B-cells; however, in other types of malignant B-cell such as non-Hodgkin lymphoma and hairy cell leukemia, expression is constitutively high (PubMed:8473738). In response to several B-cell activation signals.