CMP Sialic Acid Synthetase, also known as CMP-SAS, is a crucial enzyme in the biosynthesis of a special type of sugar called sialic acid. Sialic acid plays essential roles in various biological processes, including cell signaling, immunity, and cell adhesion. Although CMP Sialic Acid Synthetase is its most frequently used name, it is also referred to as CMP-SAS or cytidine monophospho-N-acetylneuraminic acid synthetase. These synonyms are often used interchangeably, reflecting different molecular aspects of the enzyme's function. Regardless of the nomenclature used, CMP Sialic Acid Synthetase's significance remains unchanged as a key player in the production of sialic acid, an essential component of many biological processes.