A number of signaling pathways, including Wnt/β-catenin, Hedgehog (Hh), Hippo, MAPK/ERK, and PI3K/PTEN/AKT, are involved in normal breast development.6, 7, 8, 9 Furthermore, new research shows that non-coding RNAs and epigenetic regulators possibly play a major role in the development of breast tumors and contribute to breast cancer gene diversity and metastatic features, particularly in triple-negative breast cancer.10 This evidence concerns the gene PTEN and breast carcinoma.