Otoferlin levels were reduced by approx. 28.4 ± 3.5 % in 1/3-DKO IHCs compared to Wt IHCs (relative intensities normalized to Wt; Wt n = 31 images (229 IHCs)/ N = 5 organs of Corti (3 animals); 1/3-DKO n = 20 images (196 IHCs)/ N = 5 organs of Corti (4 animals); unpaired student's t-test; ***p < 0.001; box plots illustrate the median with the interquartile range, whiskers indicate 10-90 % of data points, the squares present the respective mean value). 