They describe 13,643 differentially methylated CpG loci between policeman from two different cities; they also found two hypomethylated loci annotated to the DNA repair gene XRCC5; groups of differentially methylated loci annotated to the same gene were linked to diabetes mellitus, respiratory diseases, the dopaminergic system of the brain and neurodegenerative diseases. The gene discussed is XRCC5; the disease is neurodegenerative disease.