KRT5 and neoplasm: Results of a histochemical stain showed tumor cells positively stained by periodic acid Schiff (PAS) and PAS with diastase indicated the presence of glycogen (Figure 2H) In contrast, the tumor cells tested negative for CK-5/6, CK-20, vimentin, thyroglobulin, CD10, CDX2, epithelial membrane antigen (EMA), transcription factor E3 (TFE-3), α-inhibin, Hep-par-1, glypican-3, p63 and HMB-45 (data not shown).