It has been shown that GRIK3 is enriched in the neuroactive ligand receptor interaction pathway and haploinsufficiency of GRIK3 may be responsible for the severe developmental delay.2, 9, 10 Interestingly, a previous study indicated that, in breast cancer, multiple estradiol (E2) stimulated or inhibited genes also enriched in the neuroactive ligand receptor interaction pathway were able to affect the cell proliferation.11 On the basis of the current studies, we proposed that GRIK3 might function in the development of breast cancer. Here, GRIK3 is linked to breast cancer.