SLC6A4 and Anxiety: In a study with fifty elite athletes (involving six volleyball players) and one hundred unrelated healthy controls, genes involved in muscle development (Myostatin (MSTN)) and the management of aggressiveness, anxiety, and fear (Solute Carrier Family 6 Member 4 (SLC6A4), Solute Carrier Family 6 Member 3 (SLC6A3), and Monoamine Oxidase A gene (MAOA)) were evaluated.