 Expression and activity of ARSB were found to be related to the function of cystic fibrosis transmembrane conductance regulator (CFTR), the membrane channel deficient in cystic fibrosis.Measurements in cystic fibrosis cell line IB3 and its derivative cell line C38, which has a functional CFTR, showed increased ARSB activity and expression in the C38 line.CFTR potentiator VRT-532 increased ARSB expression and activity in cystic fibrosis cells to the level in the normal bronchial epithelial cells.