Comparative analysis of FSHD STIR+ muscle and DUX4-induced iDUX4 mouse muscle revealed overlapping expression of key MMPs (MMP2, -14, -17, -19) and MMP-associated genes (e.g., CYBA, FBLN1, TIMP1), further supporting the relevance of the iDUX4 model to human FSHD (13, 17, 59). Here, TIMP1 is linked to facioscapulohumeral muscular dystrophy.