Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
CRISPR gets the glory in landmark approval, but haemoglobin research made it possible
Stuart Orkin, of Harvard Medical School and HHMI, discusses how the discovery of BCL11A paved the way for Vertex and CRISPR Therapeutics’ exa-cel therapy for haemoglobinopathies.
With the UK’s approval of Vertex and CRISPR Therapeutics’ exagamglogene autotemcel (Casgevy) for sickle cell disease and beta-thalassemia in November, expectations are high that the FDA will soon follow suit with their first green light for a gene-editing modality. But while the CRISPR–Cas9 editor that exa-cel uses is getting much of the credit, the therapy was enabled by decades of research into haemoglobin biology. In particular, the discovery of the transcription factor BCL11A unlocked the gene-editing opportunity.