In addition, the family comprises potential pharmaceutical targets, such as B0AT2 (SLC6A15), ATB0,+ (SLC6A14) and SIT1 (SLC6A20), which are genetically associated with depression, cancer and severity of Covid-19 infection, respectively (5, 6, 7, 8, 9, 10, 11). Here, SLC6A15 is linked to major depressive disorder.