This provides a biological rationale for combining inhibitors of PD-1 with TGFβ1 inhibitors for treating cancer patients, since they can target both PD-L1/PD-1 and the TGFβ pathway facilitating T cell penetration into the tumor microenvironment generating enhanced antitumor immunity and potentially reducing of the malignant cell burden (51). Here, TGFB1 is linked to cancer.