S100A4 and breast cancer: Available reports suggest that S100A4 may enhance the resistance of pancreatic cancer cells to gemcitabine by suppressing apoptosis (47, 48), increase the resistance of colon cancer cells to MTX via the Wnt/β-catenin pathway (49), and its elevated expression correlates with docetaxel resistance in advanced prostate cancer (50), tamoxifen resistance in breast cancer (51), cisplatin resistance in laryngeal carcinoma (52), and drug resistance in leukemia (52).