PADI4 and cancer: Our findings that citrullinated proteins and PAD4 are overexpressed in HPV-positive cervical cancers support the role of citrullination in HPV transformation, in agreement with the higher expression of PADI4 genes found in various malignant tumor tissues, as well as in the blood of patients with some cancers (Chang et al., 2009; Yuzhalin, 2019).