HTR1A and male reproductive organ cancer: Biological explanations for PE include: evolutionary theories, penile hypersensitivity, central neurotransmitter levels and receptor sensitivity (hyposensitivity of the 5-HT2C and/or hypersensitivity of the 5-HT1A receptors suggested for lifelong PE), the degree of arousability, the speed of the ejaculatory reflex and the level of sex hormones (12) and finally lower urinary tract infection like prostatitis.