For further investigation of the mechanism of serum derived exosomal hsa-circ-0004771 in 5-FU resistance in CRC, we indirectly verified that miR-653 was a target gene of hsa-circ-0004771 (Figs. 3B, 5E, H, J, K), and ZEB2 was a target gene of miR-653 (Fig. 5E, J, L), and miR-653/ZEB2 axis was a pathway targeted by hsa-circ-0004771 (Fig. 5E, I, J) in CRC based on the data from previous studies [25]. The gene discussed is ZEB2; the disease is colorectal carcinoma.