Further, we aim to determine the relationship between the severity of cervical histology and the intensity of p16INK4a and ki-67 staining ; then to evaluate the expression of p16INK4a and ki-67 in correlation with biological and socio demographic parameters, and finally to evaluate the correlation of p16INK4a and ki-67 staining with high-risk HPV 16 and18 infection. The gene discussed is CDKN2A; the disease is infection.