PTEN and adenocarcinoma: Our study examined murine prostate cancer cell lines developed to mimic the common genetic mutations in prostate cancer patients with castration-resistant disease: MYC, RAS, PTEN, and TP53. The proto-oncogene MYC is expressed in approximately 40% of primary adenocarcinomas and 90% of metastases, with metastases often displaying gene amplification (60, 61).