TP53 and choreatic disease: Mutation analyses among high-risk Chinese populations have demonstrated that p53 gene mutations occur at an early stage of oesophageal carcinogenesis, both in the setting of basal cell hyperplasia (BCH) and in dysplastic lesions (Bennett et al, 1992; Wang et al, 1993; Gao et al, 1994; Jaskiewicz and De Groot, 1994; Parenti et al, 1995).