Although, a high pHi level is kept at a constant level in cancer cells by the plasma membrane ion transporters and the pHi regulators such as the sodium and hydrogen exchanger 1 (also known as NHE1) [114,117], carbonic anhydrases (also referred to as CAs) [118,119], monocarboxylate transporter 1 and 4 (i.e., MCT1 and 4) [115], as well as a sodium-driven bicarbonate exchanger [120,121,122]. Here, SLC9A1 is linked to cancer.