POU2F1 and hepatocellular carcinoma: Simultaneous incubation with TEA and 2 μM Ro 31–8220 for a short time (5 min) resulted in a marked inhibition of TEA accumulation in HEK-OCT1 cells and also in human hepatoma HepaRG cells (Fig 3A), which constitutively exhibit OCT1 activity in an hepatic environment [30].