In the initial screening process, we found some factors that might cause the spread of T. vaginalis, including religious beliefs, sexual orientation, cervical intraepithelial neoplasia (CIN), the number of CD4 cells, the number of female pregnancies, male circumcision, the use of female intrauterine devices and hormone contraceptives, sexual practices, menstrual cycle, and the types of latrines [3, 22, 24, 90]. The gene discussed is CD4; the disease is cervical intraepithelial neoplasia.