cdc6 is a key factor of DNA replication license system, DNA replication initiation complex, which plays an important role to ensure DNA replicate only once during the one cell cycle.12, 13 Several studies have showed that cdc6 has the character of oncogene and also plays an important role in the evaluating tumor grade, screening tumor cell and predicting prognosis by probing it in the tissue or exfoliated cells.14, 15, 16, 17 Its expression and detection in peripheral blood of patients with tumor remain unknown. The gene discussed is CDC6; the disease is neoplasm.