'Shrinking' Season 3, episode 1 has the perfect celebrity cameo

Shrinking is back for Season 3, and the first episode has already made us feel all the feels.

But aside from the episode's poignant ending, there's also a surprise celebrity cameo that has people talking: Back to the Future star Michael J. Fox, who pops up in a memorable scene with Harrison Ford.

So who does Fox play, and why is it significant?

Who does Michael J. Fox play in Shrinking Season 3?

At the start of the episode, Paul (Harrison Ford) visits a neurology clinic to discuss the tremors he's experiencing in his left hand as a result of Parkinson's disease. While waiting for his appointment, he takes a seat in next to a man who asks him what he's in for.

"Parkinson's," responds Paul. "You?"

"Just a haircut," comes his reply.

The man, Gerry (Michael J. Fox), goes on to have a conversation with Paul about Parkinson's disease and the various symptoms that can come as it progresses, including changes to speech, postural instability, muscle stiffness, chronic pain, and hallucinations.

"Enough whining," says Gerry at the end of their chat, shortly before Paul is called in. "I'm still here, so f*** Parkinson's."

Paul repeats it back as he follows the doctor. "F*** Parkinson's."

What's the significance of Fox's cameo?

The cameo is particularly significant because Michael J. Fox himself has Parkinson's disease: He was diagnosed with early-onset Parkinson's in 1991 at the age of 29, after noticing a tremor in his finger.

After making his diagnosis public in the late '90s, Fox launched a foundation to spread awareness and raise money for Parkinson's research. In 2025, he was awarded the Presidential Medal of Freedom for his advocacy.

Fox's cameo not only packs an emotional punch in Shrinking, but it also continues to spread awareness about the various symptoms that the disease entails.

Shrinking Season 3 is now streaming on Apple TV with new episodes Wednesdays.