CTSD and breast cancer: KYNU, CTSD and PMP22 are known to be up‐regulated in advanced metastatic cancers and correlate with poor prognosis whereas LAMB1 encodes a laminin‐1 protein shown to have reduced expression in breast cancer (Minn et al., 2005; Pruitt et al., 2013; Simpson et al., 2010; Tong et al., 2010).