YBX1 and esophageal squamous cell carcinoma: The elevated RNA m5C methylation observed in ESCC tumors stems from the overexpression of the m5C methyltransferase NSUN2 and the m5C “reader” Y-box-binding protein 1 (YBX1) (Liu L. et al., 2024; Niu et al., 2022; Su et al., 2021).