.@RobinRoberts, Barack and I have you in our prayers. We believe in you and thank you for bringing awareness and hope to others. –mo— Michelle ObamaMichelle ObamaTrump’s first 100 days saw liberal media derangement reach new heights Dems, GOP bicker via official Twitter accounts Bill Maher to Dems: 'When they go low, you go lower' MORE (@MichelleObama) June 11, 2012
Roberts announced her tweet was regarding "something I have been dealing [with] for the last couple months" on ABC's "Good Morning America" Monday morning.
Obama's Twitter feed directed followers to Roberts's post in order to understand the diagnosis. Roberts is also encouraging readers to sign up to be bone marrow donors.
Roberts has interviewed the first lady in the past, as recently as late last month, when Obama was promoting her book, American Grown.