EPCAM and hepatocellular carcinoma: Although the liver is an epithelial organ, the majority of hepatocytes or hepatocellular carcinoma (HCC) cells are EpCAM negative [14]–[17], and the EpCAM-based strategies are not appropriate for detection of HCC CTCs [18] although two studies have recently been conducted to detect EpCAM-positive CTCs as circulating cancer stem cells in patients with HCC [19], [20].