Epidemiological data indicate that genetic and environmental factors interact to determine an individual's risk of developing multiple sclerosis (MS). Handel et al. examine the key periods of life during which the environment might contribute to MS susceptibility, focusing on three putative MS risk factors: sun exposure (and its relationship with vitamin D levels), Epstein–Barr virus infection, and smoking.
- Adam E. Handel
- Gavin Giovannoni
- Sreeram V. Ramagopalan