Given that ERα-positive breast cancer patients with increased TUBB showed worse prognosis (worse OS, RFS, and DMFS) and ERα-negative breast cancer patients with increased TUBB showed better prognosis (better OS, RFS, and DMFS), this suggests that the expression of TUBB might be a predictive biomarker for worse prognosis in ERα-positive breast cancer patients and better prognosis in ERα-negative breast cancer patients. The gene discussed is TUBB; the disease is breast cancer.