Another important aspect seems to be the exact antibody format or targeting moiety used, as some TABs targeting HER2 on breast cancer cells are found to be insensitive to PD1-PD-L1 mediated T cell suppression toward their activity, while blockade of the axis might enhance the lytic potential of another anti-HER2 TAB (48, 49). Here, ERBB2 is linked to breast carcinoma.