In addition to the development of novel agents, older biologic therapies with well-known risk profiles are being applied in new settings such as combination monoclonal antibody and small molecule therapy for chronic lymphocytic leukemia, maintenance immunotherapy following allogeneic HCT or CAR T-cell therapy, and use of Janus kinase inhibitors or tumor necrosis factor-α (TNF-α) inhibitors for treatment of graft-versus-host disease [25–32]. The gene discussed is TNF; the disease is graft versus host disease.