CDKN2A and cervical cancer: Notably, 21 cases of CIN2+ (9.1%, 21/231), including 8 cases of CIN2 (19.0%, 8/42), 8 cases of CIN3 (6.7%, 8/119) and 5 cases of cervical cancer (7.1%, 5/70) were p16/Ki-67 negative.