First, we have found that in the majority of lesions analyzed the wild-type PTEN allele is retained (findings summarized in Supplementary Table 1): thyroid papillary and oxyphilic cell carcinomas from patient II (25, 36), breast carcinoma from patient IV (24), colon polyps from patients Ia and IXa (31), labial verruca from patient Ia and melanoma from patient VII (present study). This evidence concerns the gene PTEN and breast carcinoma.