PROCR and facioscapulohumeral muscular dystrophy: Clustering FSHD muscles as STIR−/T1−, STIR−/T1+, STIR+/T1− and STIR+ T1+ according to the MRI findings, we observed that the number of CD201+ cells per number of fibres significantly increased in both STIR+/T1− and STIR+/T1+ muscles compared with controls, and in STIR+/T1+ compared with STIR−/T1− (Fig. 3D).