NRG1-NRG1 neuroimaging epistasis. On the background of the risk genotype for rs4560751 (1/1), the activation within left Brodmann area 10 (Talairach coordinates -27 48 24) increased in a dose dependent manner for risk allele carriers with the most inefficient processing (highest activation) for the rs3802160 homozygotes (G1-G3 groups: rs450751- 1/1; rs3802160- 1/1, 1/2, and 2/2 respectively; G4-G6 groups: rs4560751- 1/2; rs3802160- 1/1, 1/2, and 2/2 respectively).