Together with the notion that a high level of HDAC4, HDAC5 and HDAC6 expression has an implication in cancer development [48–50], the up-regulation of HDAC4, HDAC5 and HDAC6 of fPMSCs showed in this study may imply a potential risk for malignant transformation for this type of cells. This evidence concerns the gene HDAC4 and cancer.