Given the known roles of p53 isoforms in regulating the functionality of the wild-type protein, both negatively and positively depending on the context, with Δ40p53 and p53β capable of modulating gene expression and defining cell responses to cell signals in a p53-dependent and independent manner, our previous results have clear implications for the ability of TP53 to function as a tumour suppressor in breast cancer. This evidence concerns the gene TP53 and neoplasm.