UCHL1 and hepatocellular carcinoma: UCHL1 has been identified as a cancer-specific methylated gene, and silenced by promoter methylation in multiple tumors including nasopharyngeal (NPC) [11], [12], esophageal squamous cell (ESCC) [13], [14], gastric [15], hepatocellular (HCC) [15], colorectal [15], renal cell [16], and ovarian carcinomas [17].