MMP28 and pachyonychia congenita: In addition, MMP28 enhanced EMT when TGF-β signaling pathway was activated, and downstream Snail transcription was upregulated.[47] Researchers also reported that the reason why high MMP28 indicated worse prognosis was associated with Notch3 signaling pathway.[21] The mechanism of MMP28 in PC, however, needs to be further elucidated.