Candidate-based approaches have previously reported that ApA plays a role in regulating biological processes such as the production of membrane-bound and secreted immunoglobins (Alt et al. 1980; Rogers et al. 1980; Early et al. 1980), T-cell activation (Sandberg et al. 2008), hippocampal neuron stimulation (Flavell and Greenberg 2008), embryonic development (Ji et al. 2009; Mangone et al. 2010; Hilgers et al. 2011), lymphomas (Singh et al. 2009), and breast cancer (Fu et al. 2011). This evidence concerns the gene ENPEP and breast carcinoma.