POSTN and breast neoplasm: The observation of myoepithelial genes such as SFRP2, DCN, POSTN, LUM, COL1A2 and COL11A1, which showed higher expression in ER-positive compared to ER-negative breast tumours in two other breast cancer tumour profiling studies [48,49], proved the value of such an approach and demonstrated the heterogeneity of breast tumours with respect to the levels of luminal epithelial and myoepithelial gene expression.