REPORT FROM THE AMERICAN ACADEMY OF NEUROLOGY (AAN) ANNUAL MEETING, NEW ORLEANS LA, APRIL 21-28, 2012 – The preliminary results of a genome-wide association study (GWAS) suggest that combined smoking and caffeine consumption may interact with single-nucleotide polymorphisms (SNP) to reduce PD risk in some individuals (Gao et al. AAN 2012; abstract PD4.003).