An Unusual Nicotinamide Derivative, 4-Pyridone-3-Carboxamide Ribonucleoside (4PYR), Is a Novel Endothelial Toxin and Oncometabolite

Lung metastasis and endothelial function were analyzed together with blood nucleotides, plasma amino acids, nicotinamide metabolites, and vascular ectoenzymes of nucleotide catabolism.