SLC29A1 and hepatocellular carcinoma: CFA is a slightly lipophilic drug, entering into the cells by passive diffusion across lipid membranes, and via ENT1, ENT2, CNT2, and CNT3 [20], of which human ENT2 [16] and maybe ENT1 seemed to be the nucleoside transporter that is up-regulated slightly in HCC [5], and is homologous to the woodchuck counterpart.