Studies assessing either immunohistochemically detectable p53 and/or TP53 mutations in breast cancers and response to chemotherapy differ in their findings as to their value as predictors (Bergh et al, 1995; Elledge et al, 1995; Stal et al, 1995; Aas et al, 1996; Thor et al, 1998; Berns et al, 2000; Rahko et al, 2003). The gene discussed is TP53; the disease is breast carcinoma.