PCNA and cancer: Thirdly, a variety of growth factors and proliferating factors, such as epidermal growth factor (EGF), transforming growth factor (TGF), fibroblast growth factor (FGF), proliferating cell nuclear antigen (PCNA), Ki67, and Cyclin D1, are strongly involved in cell proliferation, differentiation, invasion and migration, thus regulating the prognosis of cancer.