5-fluorouracil (5-FU) is a typical antitumor drug, and circPVT1 has been found to inhibit the chemoresistance of ESCC cells to 5-FU by influencing ferroptosis and the Wnt/b-catenin pathway via the miR-30a-5p/Frizzled3 (FZD3) axis (Yao et al., 2021). Here, FZD3 is linked to esophageal squamous cell carcinoma.