ABCG2 and hepatocellular carcinoma: In addition, HCC patients who carry the genetic variants rs2231137 (c.34G>A, p.Val12Met) and rs2231142 (c.421C>G/A, p.Gln141Glu/Lys) of ABCG2 and rs1045642 (c.3645T>G, p.Ile1215Met) of ABCB1 have lower plasma levels of sorafenib and show better progression-free survival [11].