SLC9A3 and infection: Also, cytoplasmic pH homeostasis was required for IBV cell entry when tenapanor was supplemented to cells between −2 and 0 hpi, 0 and 2 hpi, 2 and 4 hpi, and 4 and 6 hpi, suggesting that NHE3 activity was required for early infection stages (Fig. 8A).