Fuente: WIPO "tomato" Among the strategies allowing cancer cells to escape the immune system, the presence of Transforming growth factor beta (TGF-β) in the tumor micro-environment (TME) is one of the most potent immunosuppressive mechanisms for many types of tumors. Thus, depleting TGF-β is regarded as a promising potent therapeutic approach to fight cancers, regardless of the type of tumor. However, the major impediment for achieving this objective is that TGF-β belongs to the few cytokines that must be activated once secreted. Moreover, a systemic targeting of TGF-β is associated with profound side effects due to TGF-β ability to sustain the homeostasis of numerous tissues. Hence, selectively targeting of TGF-β activation within the TME appears as a rational approach to boost the anti-tumor response and avoid side effects. The integrin αvβ8 expressed on Tregs specifically promotes TGF-β activation and impairs the anti-CD8 T cell response within the TME of different cancers in both mice and humans. The inventors generated anti-β8 chain of αvβ8 integrin (Itgβ8) neutralizing monoclonal antibodies which specifically bind to Tregs and selectively neutralize the ability of Tregs to activate the TGF-β. Thus, the present invention relates to isolated anti-Itgβ8 neutralizing antibodies which specifically binds to β8 chain of αvβ8 integrin (Itgβ8) expressed on Tregs, and their uses for treating cancer.