The tumour volume was reduced by approximately 61% in the [131I]IITM group compared with that in the control group; moreover, [211At]AITM showed better therapeutic efficiency (reduction in tumour volume by 73.48% at a 1.11 MBq dose).208 Because most conventional strategies regulate mGluR1 activity through antagonists, this approach is susceptible to metabolic compensatory regulation. Here, GRM1 is linked to neoplasm.