TP53 and breast cancer: This indicates that Δ133p53 (α, β, γ) isoforms are not randomly expressed in breast cancers, confirming that the internal promoter of TP53 and the alternative (β, γ) splicing of p53 mRNA are regulated in tumor cells (Aoubala et al., 2011; Marcel et al., 2014; 2010; Tang et al., 2013).