Tesnatilimab (JNJ-64304500) is a human IgG4 monoclonal antibody targeting Natural Killer Group 2D (NKG2D), an activating receptor expressed on NK cells, CD8⁺ T cells, and γδ T cells. It binds to NKG2D to block its interaction with ligands (e.g., MIC-A/B, ULBP family) often overexpressed on stressed or malignant cells, thereby modulating immune activation. It is being developed for the treatment of autoimmune diseases, such as rheumatoid arthritis and Crohn's disease, aiming to suppress pathogenic immune responses.