Last night on ABC World News, George Stephanopoulos announced an astonishing 1,000 percent increase in the number of people registering to become bone marrow donors in the 24 hours following Robin Roberts’ announcement that she has a rare blood and bone marrow disease. Roberts shared the sad news during the GMA broadcast on Monday while sitting side-by-side with her colleagues, including Stephanopoulos.

According to the Be The Match registry, more than 3,600 people have signed up to become potential donors. An average day usually sees between 200 and 300.