We hypothesized that AS is associated with impaired 5HT clearance due to reduced serotonin receptor (SERT) expression and increased 5HT receptor (HTR) activity.<h4>Methods</h4>Sixty-six patients with severe AS undergoing aortic valve (AV) replacement were enrolled in the study, and samples from their explanted AV were harvested. This evidence concerns the gene SLC6A4 and aortic stenosis.