Pro-Arc Diagnostics is a developing next-generation laboratory test for patients at risk of Progressive Multifocal Leukoencephalopathy (PML). PML is caused by the John Cunningham Virus and is responsible for thousands of deaths each year. To date, doctors have had no way to determine which patients were at risk for developing PML. Pro-Arc’s technology is being designed to identify these patients, which may eventually allow doctors to monitor PML risk and safely design treatment courses in response.