TNFRSF9 and neoplasm: Other arguments supporting the evaluation of anti-HER2 in combination with ICI include the frequent expression of PD-L1 in HER2-positve BC and its association with survival [77], as well as the improvement in the anti-tumor activity of anti HER2 antibodies in the presence of anti-PD-1 or anti-CD137 antibodies in mouse models [76].