XRCC5 and respiratory system disorder: 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.