FGF21 goes up during starvation, fasting, fatty acid oxidation disorders, and - interestingly - it is also now a biomarker for mitochondrial disease:
http://www.cell.com/...1247(16)30501-0
https://www.ncbi.nlm...pubmed/21820356
Does anyone know of a commercial lab in the US that is testing FGF21 in humans? I couldn't find it on the Labcorp or Quest menus, which doesn't mean it is not available.
Edited by pone11, 30 May 2017 - 10:23 AM.