SLC9A1 and central nervous system cancer: Although NHE1 inhibitors are known to effectively retard cell proliferation of different malignant tumor cells [8–11], we have shown that NHE5 knockdown by shRNA markedly diminishes the proliferation and invasion of C6 glioma cells, and demonstrate that NHE5 knockdown has a significantly different effect on tumor growth and invasion in mouse xenografts compared to the impact caused by NHE1 knockdown.