Protease activity is the enzymatic process by which proteases, also known as proteolytic enzymes, break down proteins into smaller peptides or amino acids. Proteases play a crucial role in various biological processes, such as protein digestion, cell signaling, and regulation of gene expression. Abnormal protease activity has been implicated in various diseases, including cancer, Alzheimer's disease, and autoimmune disorders. Research in protease activity focuses on understanding the mechanisms of protease function, identifying new proteases, and developing inhibitors to modulate protease activity for therapeutic purposes.