CD28 and melanoma: In this respect, a CD28/OX40 CAR-T cell targeting disialoganglioside (GD2)-positive solid cancers, such as melanoma, neuroblastoma, osteosarcomas, and some other sarcomas, is the first OX40-based G3 CAR-T cell being evaluated in a clinical trial for the treatment of metastatic melanoma (NCT02107963).