Final answer:
TREGs, or regulatory T cells, are protective against conditions such as inflammatory bowel disease, HIV disease, and MRSA.
Step-by-step explanation:
TREGs, also known as regulatory T cells, are a type of immune cell that helps maintain immune homeostasis and prevent autoimmune diseases. They play a crucial role in suppressing excessive immune responses and inflammation. TREGs have been shown to be protective against several conditions, including A. Inflammatory bowel disease, B. HIV disease, and D. MRSA.