SLC2A1 and breast cancer: A myriad of studies showed that elevated expression level of GLUT1 in malignant tumors was correlated with poor clinical outcomes in patients with diverse types of solid tumors such as lung cancer [14, 15], breast cancer [16, 17], esophageal cancer [18], hepatocellular carcinoma [10], gallbladder carcinoma [19], colorectal cancer [20–23], oral squamous cell carcinoma [24–28], bladder cancer [29], ovarian cancer [30], head and neck squamous cell carcinoma [31], and salivary gland tumor [32].