Most of the tumours initiated by ErbB2 in the mated mice appeared at least seven weeks after the completion of pregnancy, which is too late to be considered as a case of pregnancy-associated breast cancer: in humans, breast cancer diagnosed during pregnancy, breast-feeding, or within one year of giving birth is called pregnancy-associated breast cancer (Borges and Schedin, 2012). The gene discussed is ERBB2; the disease is breast cancer.