TMC2 and posterior cortical atrophy: We also found that during the second postnatal week, the Ca2+ permeability (see also “Materials and Methods” section for details) of the MET channel was similar in Tmc2+/− (PCa/PCs: P6–P7 3.37 ± 0.17, n = 7; P9 3.10 ± 0.13, n = 4) and Tmc2−/− (P6–P7 2.98 ± 0.12, n = 6; P9 3.27 ± 0.16, n = 5) OHCs.