Sen. John McCain returned to Arizona this weekend to receive therapy related to his cancer treatments as Republicans prepared a major vote for their tax overhaul bill.

A statement released Sunday from Dr. Mark Gilbert, chief of neuro-oncology at the National Institutes of Health’s National Cancer Institute, said McCain responded well to treatment he received for a viral infection.

“An evaluation of his underlying cancer shows he is responding positively to ongoing treatment,” Gilbert said. 

McCain’s office released a separate statement saying he will undergo treatment at the Mayo Clinic. 

“He is grateful for the excellent care he continues to receive, and appreciates the outpouring of support from people all over the country. He looks forward to returning to Washington in January,” his office said.

McCain announced he had been diagnosed with brain cancer in July and would begin treatment for a tumor known as a glioblastoma. 

President Donald Trump said he spoke with McCain’s wife, Cindy, and wished her well.

“But I understand he’ll come if we ever needed his vote, which hopefully we won’t,” he said. “But the word is John will come back if we need his vote. It’s too bad. He’s going through very tough time, there’s no question about it.”

McCain’s return to Arizona comes as Republicans are preparing a vote on the tax bill as early as Tuesday.

McCain voted for the Senate bill as part of a narrow majority, with only Sen. Bob Corker of Tennessee breaking from the GOP. 

McCain’s daughter Meghan tweeted thanks to her family’s supporters and suggested some charities to donate to during the Christmas season.

Thank you to everyone for their kind words. My father is doing well and we are all looking forward to spending Christmas together in Arizona. If you’re feeling charitable this Christmas @HeadfortheCure or @NBTStweets to help find a cure for brain cancer is what I recommend. ❤️

— Meghan McCain (@MeghanMcCain) December 17, 2017

Watch: Schumer Calls on McConnell to Delay Tax Vote Until Jones Is Seated