The A1/A1 homozygotes also exhibited higher prolactin concentrations and hyperprolactinemia associated adverse events [25,51] Another SNP analysis showed that in C/C homozygotes, better improvement in positive symptoms was observed in comparison to carriers of the T allele [52], additionally such male homozygotes experienced lower elevation of prolactin levels during treatment—a result consistent with findings from earlier research [25,51]. The gene discussed is PRL; the disease is hyperprolactinemia.