While we were unable to detect a decrease in Vhl transcript in whole tumor RNA from Vhl−/− PyMT+ mice (Fig. 6e), we confirmed recombination of the Vhl locus at the genomic level (Fig. 6f) and observed a significant increase in the expression of Vegfa, phosphoglycerate kinase 1 (Pgk1), glucose transporter type 1 (Glut1), TEK receptor tyrosine kinase (Tek, also known as Tie2), and platelet-derived growth factor subunit B (Pdgfb) (Fig. 6g–k), indicating that HIF downstream signaling is elevated with Vhl deletion. This evidence concerns the gene VHL and neoplasm.