Figure 4. Expression of differentiation-associated genes is associated with differentiation stage in ESCC.

Immunohistochemistry showed expression pattern of c-Jun and differentiation-associated genes in ESCC. A similar pattern of c-jun, cystatin A, involucrin and SPRR3 immunoreactivity was observed. These proteins were highly expressed in the intermediate and superficial layers in normal epithelium. c-Jun was displayed both cytoplasmic and nuclei localization in normal epithelium, whereas it was located in the cytoplasm in the tumor nest. cystatin A, involucrin and SPRR3 were predominantly localized in well-differentiation ESCC, but weakly expressed in moderately and poorly differentiated ESCC. N: nontumor tissue; W: well-differentiated ESCC; M: moderately differentiated ESCC; P: poorly differentiated ESCC.