Notably, although plexin B2 immunoreactivity is higher in peritumoral hepatocytes (Extended Data Fig. 5i,j), Plxnb2 expression is unaltered in the livers of mice bearing AKPS colon tumours, suggesting that Plxnb2 is not upregulated by primary-tumour-secreted factors nor systemic effects but, rather, due to a local response to the presence of liver metastases (Extended Data Fig. 5k). This evidence concerns the gene PLXNB2 and neoplasm.