PCNA and neoplasm: Microvessel density(MVD) is the gold standard for assessing tissue angiogenesis (3), Vascular Endothelial Growth Factor(VEGF) is a key regulator of tumor microangiogenesis (4), Ki67 and PCNA can reflect the proliferative activity of tissues (2), which are closely related to tumor aggressiveness, metastasis and prognosis (5).