TP53 and neoplasm: However, data regarding p53 expression in ACs varies in different studies; for example, studies performed by Yoon et al., (2); Karakida et al., (12); Matsuzaki et al. (10), and Nobusawa et al., (13) described p53 overexpression in almost all tumor cells of the carcinoma component, while it was negative in the benign ameloblastic areas; however, Abiko et al. (14) found that both benign and malignant areas of one case of AC were negative for p53 by immunohistochemistry.