The results have shown that the development of normal epithelium of uterine cervix to CIN and CSCC was accompanied with altered protein expression of HLA-I, TAP1, TAP2, LMP2, LMP7, ERAP1, tapasin and ERp57 from normal expression to partial loss or total loss of expression in cervical tissue specimens in Immunohistochemical analysis. The gene discussed is ERAP1; the disease is cervical squamous intraepithelial neoplasia.