Similarly, 4-1BB agonism on NK cells and the resulting strengthened ADCC showed to augment the efficacy of EGFR- or human epidermal growth factor receptor 2 (HER2)- targeted antibodies, cetuximab and trastuzumab, respectively, in cancers that may have been refractory or unresponsive to monotherapy (96, 97). Here, TNFRSF9 is linked to cancer.