SMG1 and Congenital muscular dystrophy, Ullrich type: As an example of the potential of this approach, when cultured fibroblasts from a patient with Ullrich's disease (which is caused by a PTC in the gene for the extracellular matrix protein collagen VI α2) were treated with inhibitors of the NMD factor SMG1, there was an increase in the expression of truncated collagen VI α2 which partially restored the function of the extracellular matrix.30 However, SMG1 inhibitors are unlikely to be able to be used clinically as they are toxic and are not specific for SMG1.