Host metabolism rewrites metastatic fate.

Metastatic heterogeneity has traditionally been explained by tumor-intrinsic evolution. A recent study by Peng-Winkler et al. challenges this paradigm by demonstrating that hepatic steatosis instructs colorectal cancer liver metastasis through fatty acid-dependent myelocytomatosis oncogene protein (MYC) activation. These findings identify host metabolism as an independent determinant of metastatic fate and suggest that precision oncology should extend beyond tumor genomics.