Tumor metastasis has multistage processes consisting of tumor cell proliferation, migration, invasion, intravasation, survival in blood circulation, extravasation, arrest at distant organ sites, micro metastasis formation and metastatic colonization, et al. Our studies have found that silencing XRCC1 expression had no effect on cell proliferation ability in ccRCC. The gene discussed is XRCC1; the disease is neoplasm.