TP53 and breast cancer: We detected overexpression in 36% of tumor samples (Rossner et al. 2008), which is consistent with the range reported in the literature (30–40%) (Erdem et al. 2005; Iwase et al. 2001), but we did not find evidence of heterogeneity in the ORs for the associations between PAH-related exposures and p53-positive cancer as defined by protein expression status and the corresponding PAH exposures and p53-negative breast cancer.