In P21 EdaTa ear canals with otitis externa, the skin epithelium (Fig. S4K-M) and the outer epithelial layer of the tympanic membrane was thickened and hyperkeratotic (Fig. 2E; Fig. S4N) compared with the normal tympanic membrane (Fig. 2F; Fig. S4D), and K5 staining showed that this epithelium has a porous appearance due to transmural infiltration with polymorphonuclear neutrophils, which stain with the proliferation marker KI67 (Fig. S4L-O). The gene discussed is KRT5; the disease is otitis externa.