CD28 and systemic sclerosis: Acaziocolcept, a dual ICOS/CD28 inhibitor trialed for therapeutic efficacy in a murine model of systemic sclerosis (79), inhibited collagen-induced arthritis more potently than Abatacept, and inhibited human T cell function more effectively than inhibition of either ICOS or CD28 alone, suggesting its potential therapeutic use in human disease (80).