METTL3 and cancer: In subsequent work, Pan et al. explored the mechanism by which m6A contributes to 5-fluorouracil (5-FU) resistance and found that exosomal miR-181d-5p derived from cancer-associated fibroblasts (CAFs) is promoted by METTL3 in CRC cells, inhibiting neurocalcin δ (NCALD) and mediating resistance to 5-FU (Pan et al., 2022).