The musician shared the news on social media.

Hoppus, 49, shared his diagnosis Wednesday on Twitter, revealing that he has been undergoing chemotherapy treatment.

“For the past three months, I’ve been undergoing chemotherapy for cancer,” he wrote.

Mark Hoppus

Mark Hoppus in 2018.Kevin Winter/Getty Images

“I have cancer.

I still have months of treatment ahead of me but I’m trying to remain hopeful and positive.

Can’t wait to be cancer free and see you all at a concert in the near future.

Love to you all.”

Well wishes for the rocker began pouring in immediately.

“My heart hurts so much,” one fan replied.

“Praying for you, Mark.

Kick cancer’s ass.”

“So many people you’ve never met are pulling for you,” wrote another.

“We love you Mark!”

“We love you Mark,” the brand Hot Topic tweeted.

“You got this!”

Novakalso sent his best, writing, “you’re on our minds, Mark.

Your attitude is going to be magnified by so many people.”

“Lots of love to you Mark,” wrote Billy Martin, of Blink-182 peers Good Charlotte.

“Hope you kick it’s ass soon,” wrote former KROQ and current KLOS DJ Kevin Ryder.

Hoppus is in Blink-182 withTravis BarkerandMatt Skiba.