Notably, comparisons between Amish and Hutterite farm children by Stein et al. identified IRF7 and TNF as key network hubs connecting differentially expressed genes in peripheral blood cells between these populations, both of which were over-expressed in the Amish (i.e. children with low rates of allergies/asthma and high microbial exposures) (53). This evidence concerns the gene TNF and allergic disease.