CCK-8 assays showed that circUCK2(2,3) overexpression sensitized HCC cells to multiple EGFR inhibitors, including gefitinib, vandetanib and pelitinib (Fig. 6E, Fig. S12G to I), whereas circUCK2(2,3) knockdown showed no or marginal effects (Fig. S12A–D). Here, EGFR is linked to hepatocellular carcinoma.