PTEN and cancer: TF expression in cancer is hypothesized to be induced by several mechanisms including loss of tumor suppressor genes (phosphatase and tensin homolog [PTEN] or p53), activation of oncogenes (e.g., K‐RAS and epidermal growth factor receptor variant III [EGFRvIII]), hypoxic tumor microenvironment, or transforming growth factor β [TGFβ] signaling.9