HIF1A and breast cancer: A recent meta-analysis, which included 14 studies, reported that high HIF-1α expression among breast cancer patients was an indicator of poor prognosis, and was associated with both overall survival (hazard ratio [HR] = 1.46, 95%CI 1.12, 1.92) and disease-free survival (HR = 1.91, 95%CI 1.43, 2.57) [21].