Data from sequencing of PDTC and ATC suggest, that the progression from well-differentiated thyroid cancers to ATC happens as a result of the cooperation between multiple acquired alterations such as mutations in CTNNB1 (Human β-catenin gene), PIK3CA (Phosphatidylinositol 3-kinase catalytic subunit), TP53 (Transformation related protein 53) and PTEN (Phosphatase and tensin homolog). The gene discussed is PTEN; the disease is thyroid cancer.