Washington (CNN)Cindy McCain tweeted Thursday to let the public know that her husband, Arizona Republican Sen. John McCain, is "doing fine" and not going anywhere.
Cindy McCain tweets her husband, John McCain, is 'doing fine'
"Contrary to popular belief @SenJohnMcCain is doing fine and has no intention of resigning! #crackpots," she wrote on Twitter.
It appears her tweet was in reference to some conservative commentators who posted on social media earlier in the day that McCain would step down.
Her tweet is the most recent update on the senator, who has been noticeably absent on Capitol Hill while he is being treated for a primary glioblastoma, a type of brain tumor, which he was diagnosed with last year.
Cindy McCain said in February that her husband was recovering from his last round of treatment.
"Chemo and radiation is a very tough customer," she said during a joint appearance with her daughter Meghan McCain on ABC's "The View." "It does so much good, but it also does a lot of damage, and so he's recovering from the last round of chemo and radiation. He's tough as a boot, he's at our ranch and he's watching today."
A glioblastoma is a particularly aggressive tumor that forms in the tissue of the brain and spinal cord, according to the American Brain Tumor Association.
Republican Sen. Lindsey Graham of South Carolina, McCain's closest friend in the Senate, said in December he is confident McCain will return to the Senate.
"He is receiving treatment for the side effects of therapy," Graham said. "I feel pretty good about the way the treatment is affecting his underlying cancer. But the treatment has a downside. So he is trying to rest up. I am very confident that he will come back and continue to participate for a long time to come."
McCain was the 2008 Republican presidential nominee.
This story has been updated.