“…( Massart et al, 2016 ) Other researchers have also utilized peripheral blood methylation as a less-invasive sample to study methylation patterns in chronic pain conditions, including fibromyalgia, persistent post-mastectomy pain, generalized musculoskeletal pain, and cLBP. ( Tajerian et al, 2011 , Kawi et al, 2018 , Sukenaga et al, 2016 , Burri et al, 2016 , Stephens et al, 2017 )…”