APOE and breast cancer: Gene expression analyses using the TIMER database based on TCGA data showed that APOE mRNA levels were significantly higher in breast cancer (BRCA), Esophageal carcinoma (ESCA), Head and Neck squamous cell carcinoma (HNSC), Liver hepatocellular carcinoma (LIHC), Prostate adenocarcinoma (PRAD), Stomach adenocarcinoma (STAD), Thyroid carcinoma (THCA) and Uterine Corpus Endometrial Carcinoma (UCEC) compared with the corresponding normal tissues (Figure 1).