GDF2 and breast carcinoma: BMP-2, BMP4, BMP-6, BMP-9, BMP-10, BMP-15 and GDF9a impede the proliferation of breast cancer cells (Hanavadi et al. 2007, Du et al. 2008, Alarmo & Kallioniemi 2010, Ye et al. 2010, Ren et al. 2014a).