Considering cAMP responsive element binding protein 1 (CREB1) (a sex-limited susceptibility gene for unipolar mood disorders), G to A transition at position –656 in its promoter creates a perfect match to the core of the TFCP2 binding site, reflecting a gain of function that is consistent with the dominant effect (penetrance ≥82%) of this variant on the development of depressive disorders among female heterozygous carriers [46,47]. The gene discussed is CREB1; the disease is depressive disorder.