Catalysis plays a critical role in various biochemical reactions within the immune system. Enzymes, which are biological catalysts, facilitate numerous processes such as antigen processing, cell signaling, and metabolic pathways that are essential for immune function. Some pathogens and cancer cells can manipulate catalytic processes to evade immune surveillance. For example, the overexpression of certain enzymes can lead to the degradation of immune-stimulating molecules, thereby hindering the immune response.