The most promising cancer types expected to specifically respond to these therapies are Her2/mutp53 double-positive breast cancer [constituting 72% of all sporadic Her2-positive breast cancers (52)], pancreatic and non-small-cell lung cancer [both of which have high prevalence of mutp53 (1) and are commonly treated with EGFR inhibitor Erlotinib], and possibly esophageal cancer [43% mutp53-positive (1), 23% Her2-positive]. This evidence concerns the gene ERBB2 and breast cancer.