Importantly, the observation that inhibition of apoptosis can rescue the cartilage phenotype but not the underlying transcriptional and processing defect in both Xenopus nol11 morphants and some mouse Treacher-Collins Syndrome models demonstrates that it is the evolutionary conserved nucleolar stress response, and not the ribosomal defect per se, that produces the craniofacial malformation. Here, NOL11 is linked to Treacher-Collins syndrome.