CD28 and mature T-cell and NK-cell non-Hodgkin lymphoma: The T-cell signaling pathway also has multiple candidate therapies: multikinase inhibitors, such as dasatinib (NCT01609816, NCT01643603), for PTCL; PI3K inhibitors, such as duvelisib (NCT03372057) and copanlisib (NCT03052933), for PTCL; an anti-ICOS monoclonal antibody in ICOS-PI3K pathways, MEDI−570 (NCT02520791), for the follicular variant of PTCL-NOS and AITL; and a CTLA-4 inhibitor, such as ipilimumab, for CLA-CD28 fusion-positive tumors.