CDKN2A and infection: In addition, previous work showed that a cumulative immunoscore of p16 and Ki‐67 improved accuracy and reproducibility of CIN grading compared to current practice.18 These studies and the present study showed that whereas CC shows no E4 expression and often expresses both p16 and methylation marker positivity, LSIL/CIN1 and HSIL/CIN2 are very heterogeneous and complex groups, consisting of productive infections expressing E4 and transforming lesions expressing variable p16, some of which show methylation marker positivity.