Approximately half of these ribosomal genes showed a reduction in expression levels within the range 0·5–0·8 in patients with the 5q− syndrome, including RPS14, RPS23, RPL28, RPL31 and RPL22L1. The findings of Gazda et al (2006b) indicate that some ribosomal protein genes are closely co-regulated in humans and that haploinsufficiency for RPS19 results in downregulation of the additional ribosomal protein genes in both haematopoietic progenitor and erythroid cells in DBA patients. Here, RPS23 is linked to Diamond-Blackfan anemia.