Why FDA approval of sickle cell gene therapy is a ‘big deal’

Sickle cell disease is a chronic, debilitating condition that affects nearly 100,000 Americans, most of them with African ancestry. Now, the FDA has approved a groundbreaking treatment for it that uses the gene-editing tool CRISPR. John Yang speaks with Yale School of Medicine assistant professor Dr. Cece Calhoun and New York Times reporter Gina Kolata to learn more.