Siramesine (Lu 28-179) was designed as a low-efficacy serotonin 5-HT1A agonist for treating depression and anxiety disorders [86], but it was later revealed that siramesine displayed a subnanomolar affinity for σ2R and a 140-fold selectivity for σ2R versus σ1R. The gene discussed is TMEM97; the disease is major depressive disorder.