P2RX7 and major depressive disorder: Furthermore, our findings in detecting the effect of P2RX7 variation on depression only in interaction with stress are in line with rodent models investigating humanized hP2Rx7 mice in a GxE scenario reporting that rs2230912 heterozygous mice exposed to chronic social defeat show higher anhedonia and anxiety compared to homozygotes [58], and concluding that P2RX7 plays a role specifically in stress-related pathologies [26].