S100A4 and cancer: Niclosamideinhibits S100A4 at its transcription level,25,26 and phenothiazine inhibits the S100A4 protein by inducing its oligomerizationwith an IC50 of around 100 μM.27 Pentamidine, an inhibitor of the S100-p53 interaction,has been shown to target S100A4 in vitro by interacting with the fourthhelix in micromolar-range concentrations and shows antiproliferativeactivities in cancer cells.28 Interestingly,a monoclonal S100A4 antibody has been reported to have activity ina skin fibrosis model.29 Most recently,new S100A4 inhibitors were published.