GPR55 and ovarian carcinoma: For example, LPI and its 2-arachidonolyl lysophosphatidylinositol (2-ALPI) derivative, are the most potent ligands for GPR55 (Okuno and Yokomizo 2011) with the latter being markedly elevated in ascites fluid from ovarian cancer patients (Xiao et al. 2001; Xu et al. 2001).