In another study, CD73 expression associated with poor outcome of breast cancer patients treated with trastuzumab, an anti-HER2/ErbB2 antibody, while its expression on tumor cells and host cells was linked to resistance to monoclonal antibody treatment in a mouse model of HER2/ErbB2-driven breast cancer (Turcotte et al., 2017). The gene discussed is ERBB2; the disease is breast carcinoma.