Our data suggested that the often-reported associations between CIN and gender, tumour location and stage actually comprised two separate associations: (a) between gender, distal location and group 2 tumours (CIN+ and/or TP53- mutant with wild-type KRAS and PIK3CA); and (b) between stage III and group 3 tumours (KRAS- and/or PIK3CA-mutant, CIN+, TP53-wild-type). This evidence concerns the gene KRAS and cervical squamous intraepithelial neoplasia.