Cyclosporin is useful in
Cyclosporin is an effective immunosuppressant used in the treatment of autoimmune disorders (such as rheumatoid arthritis) and in organ transplantation to prevent rejection. Cyclosporin lowers the activity of T-cells and hence, suppressing the activity of the immune system. Cyclosporin was isolated from the fungus Tolypocladium inflatum. Common side effects include high blood pressure, headache, kidney problems, increased hair growth, and vomiting. So, the correct answer is 'Immunosuppressant'.