In breast cancer, Loi et al. demonstrated that CD73 expression was significantly associated with a worse prognosis in triple negative breast cancer (TNBC) patients (n = 661, P = 0.029) but not in patients with luminal (n = 2083, P = 0.7) or HER2+ (n = 487, P = 0.86) breast cancer [26]. This evidence concerns the gene ERBB2 and breast cancer.