Solution:

A substance that suppresses the immune system’s response. It weakens the body’s defenses against infections and other disorders including cancer. To prevent a person from rejecting a bone marrow or organ transplant, immunosuppressive drugs may be used. They’re also used to treat autoimmune diseases and allergies, which are characterized by overactive immune responses.

The Trichodermapolysporum fungus produces Cyclosporin A, an immune suppressant.