Adenosine Deaminase (ADA) is a crucial enzyme belonging to the adenosine deaminase family, responsible for catalyzing the conversion of adenosine to inosine and ammonia. This enzyme primarily functions in the cytoplasm and is widely distributed in various cells and tissues, particularly in cells of the immune system. ADA is involved in purine metabolism and cell signaling, playing a vital role in immune system function. Gene expression exhibits specificity across different cell types, with high expression observed in T cells and B cells. Mutations in the ADA gene can lead to immune deficiency diseases, such as severe combined immunodeficiency syndrome (SCID).