PCNA and neoplasm: High Notch4 expression was markedly correlated with the histological grade of the tumour (p < 0.001, Chi2 test), depth of invasion (p < 0.001, Chi2Yatesa test), angioinvasion ((p < 0.001, Chi2Yatesa test) and PCNA immunohistochemical expression (p < 0.001, Chi2Yatesa test).