from another related article[1], "A working hypothesis is that socio-economic circumstances leave their mark on the epigenome leading to stable changes in expression of genes critical for human health, such as those involved in cardiovascular, immune, stress response and behavioural pathologies"

[1] Associations with early-life socio-economic position in adult DNA methylation. Int J Epidemiol. 2012 Feb; 41(1): 62–74.