CTLA4 and neoplasm: Notably, Ren et al. also showed a similar requirement for both macrophages [via production of type I interferon (IFN)] and DCs in the induction of anti-tumor T cell responses following anti-CD20 therapy, and that CTLA-4hi Treg cells, within larger (more established) tumors, may be responsible for “adaptive resistance.” This lends support for an anti-CD20/anti-CTLA-4 combination regimen.