The mean plasma enrichment (MPE)
of 13C6 phenylalanine, 13C6 tyrosine, and 15N tyrosine measured by gas chromatography/mass spectrometry
(GCMS) in patients with cancer and in healthy age-, sex- and BMI-matched control participants during a primed, continuous
infusion of 13C6 phenylalanine and 15N
tyrosine.</p