Further studies indicate that exosomes from sorafenib-resistant HCC cells are enriched with circUPF2, which enhances sorafenib resistance by promoting SLC7A11 expression and inhibiting ferroptosis.circUPF2 enhances sorafenib resistance by stabilizing the circUPF2-IGF2BP2-SLC7A11 ternary complex, which stabilizes SLC7A11 mRNA, promotes systemic Xc- function, and reduces ferroptosis sensitivity, thereby inducing drug resistance (45). The gene discussed is SLC7A11; the disease is hepatocellular carcinoma.