As far as normal cervical epithelium is p16INK4a-negative and the ratio p16INK4a-positive/ p16INK4a-negative samples increases at the advanced stages of CINs and carcinomas application of immunohisto-/cytochemical test for p16INK4a may be regarded as a supplementary (optional) test for early diagnostics of cervical cancer. The gene discussed is CDKN2A; the disease is cervical carcinoma.