SLC6A4 is a gene that provides instructions for making a protein known as the serotonin transporter. This protein is responsible for the reabsorption of serotonin, a neurotransmitter that plays a key role in mood regulation, from the brain's synapses back into nerve cells. Proper functioning of SLC6A4 is essential for maintaining balanced serotonin levels, which can influence emotional well-being. Variations in the SLC6A4 gene have been linked to different responses to stress and susceptibility to mood disorders, such as depression and anxiety. Research continues to explore how these genetic differences can affect individual mental health and treatment responses, highlighting the importance of this gene in psychology and neuroscience.