E2F2 and breast cancer: Some studies showed increased E2F2 expression in many cancer types at both mRNA and protein levels (hepatocellular carcinoma, cervical cancer, ovarian cancer, non-small cell lung cancer, breast cancer, bladder cancer and kidney cancer), which was often associated with a higher tumour grade, lymph node metastasis, lymph node invasion and a worse patient prognosis [29,30,31,32].