TNFRSF9 and autoimmune disease: ICIs work by lifting immune suppression, allowing for the reactivation of T-cell activity, while TNFSF agonists, such as OX40 and 4-1BB, further amplify T-cell activation and overcome the immunosuppressive TME, effectively transforming “cold” tumors into “hot” ones and bolstering immune responses in autoimmune diseases.