ICOS and neoplasm: FoxP3-blocking antisense oligonucleotides (ASOs) had already been tested in preclinical models and were able to decrease the number of infiltrating FoxP3-positive Tregs by 70% in vitro and in vivo, strongly modulated Treg effector molecules [e.g., Inducible T-cell Co-Stimulator (ICOS), CTLA-4, CD25, and tumor necrosis factor receptor superfamily member 9 (TNFRSF9)] increased the activation of CD8-positive T cells, and generated antitumoral activity in syngeneic tumor models (53).