FSHD muscles with progression at the 1-year MRI follow-up showed a significantly high number of both BDCA1+ myeloid dendritic cells (Fig. 5a) and CD8+ T lymphocytes (Fig. 5b), but not of CD20+ B lymphocytes (Fig. 5c) and CD4+ T lymphocytes (Fig. 5d), compared to FSHD muscles without progression. The gene discussed is CD1C; the disease is facioscapulohumeral muscular dystrophy.