The fact that sorafenib was still moderately effective in patients bearing tumors with negligible expression of OCT1 is consistent with the fact that, although OCT3 (SLC22A3) expression in normal liver tissue is markedly lower than that of OCT1, OCT3 might replace OCT1 as major organic cation transporter in some cases of HCC. The gene discussed is SLC22A3; the disease is hepatocellular carcinoma.