CCR2 and muscular dystrophy: The α-SMA+/ColI+ cells are not detectable in the fibrotic muscles of the ColI-GFP/Ccr2-/- mice either, suggesting that the lack of detectable myofibroblasts in fibrotic muscles by immunostaining is not specific to muscular dystrophy, as the muscle fibrosis in the ColI-GFP/Ccr2-/- mice following acute injury is mainly caused by poor muscle regeneration [56, 58, 59].