Several BMPs, including BMP2, BMP6, BMP9, BMP10, BMP15, and GDF9a inhibit the proliferation of breast cancer cells, whereas BMP4 and BMP7 can either promote or inhibit proliferation in different contexts (Alarmo and Kallioniemi, 2010; Zabkiewicz et al., 2017). Here, BMP4 is linked to breast carcinoma.