Mechanism of action of F508del-CFTR rescue maneuvers. A: histone deacetylase activity in the presence of indicated compounds (n = 3; **, p < 0.01 vs. control). 9-AC: 9-aminoacridine; TSA: trichostatin A. B: F508del-CFTR activity (QR) in CFBE41o- after treatment with deferoxamine (DFX, 200 μM), 1,4-DPCA (50 μM), or 2,4-DPD (20 μM) (n = 8-21; *, p < 0.05). Data were obtained by incubating the cells with compounds for 24 hours at 37 °C.