While GSDMB over-expression in human breast cancers, specially the HER2 subtype, associates with disease aggressiveness (Hergueta-Redondo et al., 2014, 2016; Molina-Crespo et al., 2019), we only detected one case of spontaneous breast carcinoma in the GB2+/+ mice. The gene discussed is ERBB2; the disease is breast cancer.