Used in research and therapeutic development targeting complement-mediated diseases. Specifically binds to the CD59 protein, inhibiting its function in blocking the formation of the membrane attack complex (MAC) in the complement system. This enables controlled activation of the complement pathway, useful in studying diseases where complement regulation is disrupted, such as paroxysmal nocturnal hemoglobinuria (PNH), autoimmune disorders, and certain neurodegenerative conditions. Also serves as a reference standard in immunoassays and antibody development platforms to evaluate binding affinity and functional activity of novel anti-CD59 agents. Investigated for potential use in enhancing immune-mediated cell lysis in cancer therapy by temporarily disabling CD59’s protective effect on tumor cells.