G protein-coupled receptor for S-geranylgeranyl-glutathione (GGG), an endogenous metabolite present in lymphoid tissues. Couples the binding of GGG to the activation of GNA13 and downstream repression of AKT activation in lymphocytes defining their positioning and growth within lymphoid organs (PubMed:25274307, PubMed:30842656, PubMed:34088745). In lymphoid follicles, confines B cells and follicular helper T cells in germinal centers (GCs) in response to GGG local gradients established by GGT5 (via GGG catabolism) and ABCC1 (via extracellular transport) with lower concentrations of GGG found in the follicular dendritic cell network region around which germinal centers are formed (PubMed:25274307, PubMed:30842656, PubMed:34088745). In the bone marrow, also in response to GGG gradients established by GGT5 and ABCC1, it restricts chemotactic transmigration of B cells, T cells and NK cells from blood vessels to the bone marrow parenchyma (PubMed:30842656, PubMed:34088745). Contributes to GNA13-dependent pathway that suppresses GC B cell growth (PubMed:25274307). {ECO:0000269|PubMed:25274307, ECO:0000269|PubMed:30842656, ECO:0000269|PubMed:34088745}. This is the function of P2RY8 (P2Y receptor family member 8, ENSG00000182162).