Quantitative PCR was performed for MAFbx expression. With the exception of ST muscles in litter 2, MAFbx was more highly expressed in all PCS muscle samples compared with the corresponding normal muscles. Results of each litter are expressed as mean ± standard deviation from triplicate samples within the same experiment. Combined results of 4 sets of PCS piglets also tested for significance (*p < 0.05) in differences between pair-wise combinations of the least square means. Norm = normal; PCS = porcine congenital splayleg.