GRM1 and glioma: mGluRs signaling was initially implicated in cellular proliferation of glioma cells [7] and melanoma development [8] either in in vitro or in vivo studies and subsequently this receptor was shown to play a crucial role in various types of cancers [9], [10], [11], [12] Oncogenic function of mGluR1 was shown by the induction of transformed phenotype with overexpression of GRM1 gene in melanocytes [13].