NTN1 and colorectal cancer: Fang X et al. found that the lncRNA PCAT1 is abnormally highly expressed in the exosomes of colorectal cancer cells and that the lncRNA PCAT1 can promote the occurrence of the epithelial–mesenchymal transition (EMT) in circulating tumour cells by regulating the miR-329-3p/netrin-1 axis to ultimately promote colorectal cancer liver metastasis progression [45].