PAX7 and Facioscapulohumeral dystrophy: As a classification threshold for PAX7-affected versus non-affected biopsies could not be defined based on the scores in control biopsies, for further subgroup comparisons we classified the ten FSHD samples with the highest PAX7 score as PAX7HIGH (i.e. likely non-affected) and the ten FSHD samples with lowest PAX7 scores as PAX7LOW (i.e. most-affected) (Fig. 2b).