Question: What is the other name for a subastance , when bound to various radionuclides, is used in the treatment and diagnosis of certain types of cancer, and  is one of the 20 standard amino acids that are used by cells to synthesize proteins?
Sentence (from "Amino acid synthesis"): Humans are an excellent example of this, since humans can only synthesize 11 of the 20 standard amino acids (a.k.a. non-essential amino acid), and in time of accelerated growth, histidine, can be considered an essential amino acid.
Relevant evidence: No