Used in immunotherapy research and development, particularly in cancer treatment. Helps modulate the immune system by blocking the CTLA-4 receptor on T-cells, enhancing immune activation and anti-tumor responses. Employed in preclinical studies to investigate checkpoint inhibition mechanisms and to develop biosimilar or improved therapeutic antibodies. Also utilized as a reference standard in binding assays, functional assays, and quality control during manufacturing of anti-CTLA-4 biologics. Supports the development of treatments for melanoma, renal cell carcinoma, and other malignancies where immune checkpoint pathways play a critical role.