The expression of GRIK3 was found in rhabdosarcoma, neuroblastoma, thyroid tumor, lung cancer, breast cancer, astrocytoma, multiple myeloma, glioma, and colorectal cancer.7 Moreover, the GRIK3 gene was found to be methylated across all stages of lung adenocarcinoma, indicating that GRIK3 might be an epigenetic marker for diagnosis.8 Recently, Gong et al9 showed that GRIK3 expression could serve as an independent prognostic biomarker and a novel treatment target for patients with gastric cancer. This evidence concerns the gene GRIK3 and breast cancer.