Recently, Liu et al.33 showed that, unlike chimeric antigen receptor (CAR)-T cells (which induce substantial toxic effects), CAR-NK cells targeting CD19+ cancers were not associated with the development of CRS, neurotoxicity, or graft-versus-host disease, and an increase in expression of inflammatory cytokines (including IL-6) was not observed. The gene discussed is IL6; the disease is graft versus host disease.