In their study, Sveen et al. 21 showed upregulation of muc5ac.2/4 and muc2.1/2 in gills after handling stress, but the FC for muc5ac.2/4 (i.e. FC = 0.8) was significantly lower than the one reported here for muc5 upon parasitic infection. This evidence concerns the gene MUC5AC and parasitic infectious disease.