In addition to primary HCC, in mice with CRC, an unhealthy gut microbiome stimulates the secretion of metastasis-related secretory protein cathepsin K, which potentiates the development of CRC-derived metastatic hepatic cancer via M2 polarization of TAMs.395 Intriguingly, in the setting of gut dysbiosis, tuft cell-derived IL-25 enters the liver and then triggers macrophage activation, facilitating hepatocarcinogenesis and the migration of HCC cells by chemokine CXCL10.396. This evidence concerns the gene CTSK and hepatocellular carcinoma.