Amino acid-based therapy for Regenerating the lost pancreatic β-cells in Diabetic patients:Tryptophan, an essential amino acid and precursor of the neurotransmitter serotonin and the sleep hormone Melatonin, increases the expression of IGF1R, INSR, and IRS2, and promotes an insulin-sensitized state via up-regulation of  its target gene Lin28, 14/March/2018, 10.53 pm