However, the expression of HK2 in breast cancer (Curtis et al., 2012), colorectal cancer (Kaiser et al., 2007; Gaedcke et al., 2010; Hong et al., 2010) and leukemia (Stegmaier et al., 2004; Andersson et al., 2007; Haferlach et al., 2010) was lower than that in normal tissues. This evidence concerns the gene HK2 and breast cancer.