CDKN1A and neoplasm: Also, the correlation between the expression levels of p21 (CDKN1A), D-type cyclins (CCDN1-3) and p53 (TP53) was significant in TP53 wild-type, colorectal adenocarcinoma (Figure 4B) and was maintained in other tumours types, for at least one D-type cyclin (supplementary Figure S9, available at Annals of Oncology online).