The DW gene expression statistic assesses the change in connectivity of a single gene to all other genes in the network (N = 7545); the statistic counts the number of pairwise gene correlations that show a statistically significant change between the two selected groups, followed by identification of genes enriched in changing correlations/network edges. The data again point to the broad effect selection had on the shell transcriptome. Twenty-six percent of the genes included in the network analysis showed a significant change (FDR < 0.05), indicating moderate effects on transcription that are dispersed among many genes. Not surprisingly many of the DW genes have been associated with a variety of alcohol phenotypes, including preference for Grid2, Mapk1, Mapk8ip3, Pde4b, Psen1, Shank3 and Snap25 (Mulligan et al. 2006). Of some note, the DW genes were significantly enriched in cell–cell adhesion genes, including 4 cadherin and 18 protocadherin genes. Previous studies have implicated Cdh11, Cdh12, Cdh13, Cdh19 Pchha9 and Pcdh15 in alcoholism or preference (Edenberg et al. 2010; Liu et al. 2009; Lydall et al. 2011; Mulligan et al. 2006; Sokolov et
