Abstract
Immunoregulatory enzymes, which function both as biological catalysts and regulatory elements, play a crucial role in controlling immune responses. Dysfunction of these proteins can contribute to various pathological conditions, such as the suppression of antitumor immunity or impairment of anti-infectious immune responses. This review discusses the most extensively studied immunoregulatory enzymes, including indoleamine 2,3-dioxygenase 1, arginase 1, inducible nitric oxide synthase, glyceraldehyde-3-phosphate dehydrogenase, and ectonucleoside triphosphate diphosphohydrolase 1. Their classification is provided, along with an analysis of the distinctive characteristics inherent to this group of enzymes. Additionally, new directions for the medical application of immunoregulatory enzymes are explored.