In the R26-GB2/MMTV-NEU model, breast cancer development was monitored for a mean follow-up of 15 months in all experimental groups (WT, 457 days; GB2+/-, 459 days; GB2+/+, 448 days), while in R26-GB2/MMTV-PyMT mice we analyzed cancer development until 15 weeks of age. The gene discussed is GABBR2; the disease is breast cancer.