Tonsil epithelium is a heterogeneous lymphoid organ containing two different types of actively differentiating epithelia; the lining stratified squamous epithelium and the reticulated crypt, or lymphoepithelium. The tonsil crypts represent a specialized compartment, important in the immunological functions of the tonsil because of the immediate proximity of the epithelial and lymphoid tissues. In situ staining of tonsil epithelium suggests that expression of the simple epithelial keratins K8, K18 and K19 is located to the crypt epithelial cells. Cell culture of tonsil epithelium produces heterogeneous squamous epithelial cells in which differentiation appears to be ongoing and keratin expression patterns are consistent with those found in tonsil epithelial cells in situ. Human Tonsil Epithelial Cells are also useful tools to stablish in vitro disease models for High Throughput and High Content Screening.