Suppressor T cells, also known as regulatory T cells or Tregs, have specific functions in the immune system: 

• They actively suppress the activation and function of other immune cells when necessary.
• Prevent T-cells from attacking healthy cells.
• They prevent over-activation, maintain a balanced immune environment, and regulate immune responses at sites of inflammation. 
• They contribute to immune stability by ensuring that immune responses are appropriately controlled and do not lead to harmful outcomes.
• In some cases, suppressor T cells may suppress immune responses against tumors, allowing cancer cells to evade immune attack and hindering effective anti-tumor immune responses.