CFTR (IMAGE) University of North Carolina Health Care Caption Proteins CFTR (green) and FKBP1A (red) — a primary target of the drug Tacrolimus — in BEST4+ cells in small intestine. Credit Magness Lab, UNC School of Medicine Usage Restrictions credit properly License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.