HPN328 is a Tri-specific T Cell-Activating Construct (TriTAC) comprising three humanized antibody-derived binding domains: an N-terminal domain that binds DLL3 on tumor cells, a middle domain that binds to human serum albumin (for half-life extension), and a C-terminal domain that binds to CD3 (Fig. 3D) [56]. The gene discussed is DLL3; the disease is neoplasm.