For example, a recent paper suggests that venlafaxine-XR remission is more common in patients with major depressive disorder who 1) failed to respond to citalopram/escitalopram, 2) had CYP2D6 ultrarapid metabolism, and 3) carried certain allele combinations at SLC6A4 and SLC6A2 (56). The gene discussed is CYP2D6; the disease is major depressive disorder.