High tsMHC-II TNBC displayed core features of enhanced immune cell activation, chemotaxis and infiltration, with KAT2B acetylation of CIITA promoter regions mediating tumor cell tsMHC-II upregulation as a potential mechanism, suggesting novel therapeutic targets for enhancing tsMHC-II expression and immunotherapy response in tsMHC-II-low tumors. The gene discussed is KAT2B; the disease is neoplasm.