Furthermore, FOXP2 harbors a binding domain for the co-repressor CtBP1 (C-Terminal Binding Protein-1, Figure 3) which has been experimentally validated [34,66] and may be involved as a tumor suppressor in oncogenic processes through interaction with the BRCA1/2 breast cancer oncofactors [67,68]. This evidence concerns the gene CTBP1 and breast cancer.