P2RX7 and major depressive disorder: Recent dimensional analyses identified significant associations among three P2RX7 polymorphisms—the above mentioned rs2230912 (Gln460Arg), rs1718119 (Ala348Thr), and the non-coding variant rs1653625—and depressive symptomatology in two independent cohorts comprising patients with MDD and individuals with diabetes, who are at increased risk for developing mood disorders.