SLC4A4 and neoplasm: Therefore, it can be concluded that the control of the resting membrane potential via KCNQ1, the vectorial bicarbonate transport via SLC4A4, as well as the epithelial fluid secretion via KCNQ1 and TRPV6 were inhibited in PDAC (tumour epithelium and ML), while maintained in the normal epithelium (normal epithelium and HS).