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. This evidence concerns the gene S100A1 and cancer.