This hypothesis is based on the strict similitude between primordial germ cells and gonocytes with tumor cells of the carcinoma in situ (CIS), verified at the molecular level by the shared expression of genes involved in pluripotency and proliferation, such as NANOG, STELLAR, DPPA-5, GDF3, K-RAS, and CCND2 (126–129). The gene discussed is KRAS; the disease is in situ carcinoma.