“Several studies have shown that melanoma occurs two to six times more frequently in the Parkinson’s population than the healthy population,” says Dexter Dean, Ph.D., a postdoctoral fellow at the National Heart, Lung, and Blood Institute (NHLBI), who is presenting the work at the meeting. “What’s more, the protein involved in Parkinson’s disease, α-synuclein, is elevated in melanoma cells.”
https://medicalxpress.com/news/2021-04-amyloid-link-parkinson-disease-melanoma.html
And as we know, increased α-synuclein deposits are thought to be the culprit behind PD.