Among the 18 expression traits associated with smoking, SASH1, P2RY6 and PTGDS were systematically retrieved in all screening/validation replicates (Table S3). SASH1 is a tumor suppressor gene [49], P2RY6 encodes a G-protein-coupled receptor involved in the proinflammatory response to UDP in monocytes [50] and PTGDS encodes a prostaglandin D synthase involved in smooth muscle contraction/relaxation and inhibition of platelet aggregation, two functions known to be modified by tobacco consumption. Recently, in a GWE study of leukocytes RNA, PTGDS and SASH1 expressions were found associated with cotinine, a metabolite of nicotine used as a marker of tobacco exposure [51].
