that unique signatures may be found, particularly if studies are done with careful clinical characterization and confirmation of exposure via existing biomarkers such as ELISA for THC metabolites. It remains to be seen if these studies will be able to sufficiently distinguish a cannabis-related signature from that of tobacco smokers, which is a critical issue given the high comorbidity of tobacco smoking among cannabis users. The other design considerations, which include applicability across populations, the ability to find an epigenetic signature in accessible peripheral tissues, sensitivity, and specificity, as well as cost, all apply to this area as well and will need to be taken into consideration.
