Several recent studies provide new insight into Parkinson’s disease. Nine Parkinson’s patients showed improvements in walking and dexterity after receiving brain injections of a gene therapy to boost dopamine production, the Oxford Times reports. The treatment, ProSavin, was developed by Oxford Biomedica and is still in initial safety trails. Science News reported that H. pylori, the bacteria responsible for stomach ulcers, can trigger Parkinson’s symptoms in mice. Past studies had shown only a circumstantial link. Researchers at Louisiana State University Health Sciences Center in Shreveport aren’t sure how H. pylori triggered the disease, but they noted that the bacteria stole a cholesterol molecule from its host and modified it to resemble a tropical toxin known to cause Parkinsonism. And a new meta-analysis in the June 7 issue of Neurology found that Parkinson’s patients have double the risk of developing melanoma, a deadly skin cancer. Though there’s no clear explanation for the link, other studies have proposed that the pigment melanin may play a role in both diseases. People with lighter hair have higher rates of both melanoma and Parkinson’s.