Proteomic analysis revealed that these molecules include epithelial cell surface antigen (EpCAM), proliferation cell nuclear antigen (PCNA), tubular beta-3 chain (TUBB3), epidermal growth factor receptor (EGFR), apolipoprotein E (APOE), claudin 3 (CLDN3), fatty acid synthase (FASN) and ERBB2 [30], each of which plays a crucial role in tumorigenesis or cancer progression. This evidence concerns the gene PCNA and cancer.