No significant difference was observed between SIRT1 levels in different types of breast cancer (p = 0.353, Fig 1B), neither did they vary significantly with either tumor size (p = 0.649, Fig 1D), lymph node involvement (p = 0.205, Fig 1E), metastasis (p = 0.464, Fig 1F), ER status (p = 0.299, Fig 1G) or PR status (p = 0.283, Fig 1H). This evidence concerns the gene ESR1 and breast cancer.