Nobel-level geniuses into at last Krehl (links below) disentangled the holy grail modern “investigators” will continue to “miss” b/c a flourishing world supplementing nicotinic acid + tryptophan is the threat

https://jbc.org/article/S0021-9258(17)41258-0/pdf

https://jbc.org/article/S0021-9258(17)35190-6/pdf

https://jbc.org/article/S0021-9258(17)41384-6/pdf