FOLH1 and cancer: PSMA has been extensively studied for (i) its capacity to drive endocytosis and thereby provide the basis for PSMA-bound therapeutics, including chemoradiotherapy and HER-targeted therapies (42) and (ii) its enzymatic activity, releasing glutamate that activates mGluR GPCR-dependent signaling (8), whose role in cancer has been described extensively (9).