Republican Sen. John McCain has returned home to Arizona to spend Christmas with his family and will likely miss the GOP's tax bill vote that is expected to take place early this week.

McCain, who was diagnosed this summer with a rare and aggressive form of brain cancer called glioblastoma, will also undergo "physical therapy and rehabilitation" at Mayo Clinic over the break, according to a statement released Sunday.

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

On Friday, Republicans released the final version of the GOP tax bill that, if passed, will be a big win for President Donald Trump's administration.

Are there enough votes to pass the tax bill?

The GOP has secured support from Sen. Marco Rubio (R-Fla.) and Sen. Bob Corker (R-Tenn.), which should allow the measure to pass without McCain's vote, NBC News reported.

What's next?

The tax bill is expected to land on Trump's desk once it passes Congress. Republican leadership has indicated that they plan to hold a series of final votes on the measure early this week.

"This is going to be one of the great gifts to the middle-income people of this country that they've ever gotten for Christmas," Trump told reporters Saturday outside the White House before departing for Camp David, NBC News reported.

How is McCain's cancer treatment going?

The 81-year-old senator is responding positively to treatment, according to the senator's daughter, Meghan McCain.

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

Vice President Mike Pence is delaying his trip to the Middle East in the event he's needed to cast a tie-breaking vote in the Senate, according to Politico.

What else?

On Sunday, Trump told reporters that he'd spoken with McCain's wife, according to Politico.

“I wish John well. They’ve headed back [to Arizona]," Trump said. "But I understand he’ll come if we ever needed his vote, which hopefully we won’t."