ICOS and graft versus host disease: The blockade of CD28 and ICOS in an acute GvHD mouse model by the novel dual CD28/ICOS antagonist (acazicolcept/ALPN-101) led to improved survival in acazicolcept-treated mice compared to mice receiving a CD28-CD80/CD86 pathway antagonist (belatacept; CTLA-4-Ig) only [31].