MMP3 and hydrops fetalis: Although the function of MMP3 in HF regeneration has not yet been reported, MMP can modify the microenvironment of stem cells in bone, and MMP3 has been shown to have an impact on the maintenance of adult epithelial stem cells [28], implying MMP3, which we show is increased in early passage DPCs, has the potency to modify the hair follicle stem cell (HFSC) microenvironment “niche”, which plays a crucial role in cell fate decision.