TNFSF4 and systemic sclerosis: There is a strong rationale to evaluate T cell-targeting strategies in SSc given the importance of T cells in the early and inflammatory stages of the disease and accumulating preclinical evidence of a beneficial effects of targeted immunotherapy targeting T-cell costimulatory pathways, including OX40L, DNAM-1, or CTLA-4 [5, 8, 40].