RASSF1 and renal cell carcinoma: ASC/TMS1 tumor specific methylation may serve as a biomarker for early detection and prognosis prediction of RCC, especially when tumor suppressor gene (TSG) hypermethylation can be detected in patients' serum and urine samples, just like RASSF1A, tissue inhibitor of metalloproteinase-3 and CDH1 methylation [44].