TP53 and myelodysplastic syndrome: A critical role for p53 activation in the pathogenesis of ribosomopathies has been well established in zebrafish, murine or human disease models, including DBA,174–176 del (5q) MDS,148 SDS,153TCS177, and XL-DC.178 The nucleolar stress response triggered by ribosomal defects is the primary cause of p53 stabilization and activation.