INSR and Glucose intolerance: In particular, the so‐called “aromatic triplet,” i.e., FFY, is critically required for providing distinct structure environment and association with insulin receptors as demonstrated by genetic manipulation and amino acid replacement experiments.[18c] Moreover, mutations of either phenylalanines were found to be associated with glucose intolerance and hyperglycemia, emphasizing the importance of the two phenylalanines for insulin activity.