CFTR and Meconium ileus: For example, allelic variation near the transcription start site (TSS) of SLC26A9, which encodes an anion transporter in epithelial cells that interacts with CFTR to enhance its functional expression [9–11], has been shown to associate with aspects of CF lung disease [2], meconium ileus [12], CF-related diabetes (CFRD) [13], as well as exocrine pancreatic damage at birth [14, 15].