ICOS+ Th1-like cells play a crucial role in the antitumor effect of anti-CTLA-4 therapy, constituting the majority of tumor-specific, IFN-γ producing CD4 T cells (Carthon et al., 2010; Liakou et al., 2008; Vonderheide et al., 2010). Here, CTLA4 is linked to neoplasm.