HK1 and brain cancer: While increased levels of glycolytic enzymes were found in brain cancer cells (Chen et al., 2007; Palmieri et al., 2009), studies have demonstrated that enhanced glucose uptake is not a feature of breast cancer brain metastasis (Chen, 2007; Kitajima et al., 2008; Bochev et al., 2012; Manohar et al., 2013).