ERP29 and cystic fibrosis: As mentioned above, our interest in ERp29 derived from studies of the mechanism by which 4PBA rescues F508del CFTR trafficking in CF epithelia (Rubenstein et al., 1997; Rubenstein and Zeitlin, 1998, 2000; Rubenstein and Lyons, 2001; Suaud et al., 2011a, b).