ME1 and breast cancer: Our study identifies that ME1 expression links cancer progression and patient prognosis, including: (1) ME1 expression is dramatically upregulated in breast cancer with basal-like subtype; (2) Elevated ME1 expression is highly correlated with larger tumor size; (3) Elevated ME1 expression is significantly associated with higher grade; (4) Elevated ME1 expression is associated with shorter overall, relapse-free, and distant metastasis-free survival; (5) ME1 expression is negatively correlated with treatment outcome in breast cancer patients.