Partek Genomics Suite was used to generate RMA (robust multichip average (Bolstad et al., 2003; Irizarry et al., 2003) data for each of the arrays from brain samples. The average and standard deviation of RMA values were generated for the core probe sets in each brain region. The mean RMA values ranged from 4 to 21,734 (median = 106). Genes with expression levels at or near background (RMA < 16) were excluded from analyses (McClintick and Edenberg, 2006). When multiple probe sets represented one gene, the probe set with the largest mean expression was selected. If the mean RMA value was above 16 in at least one region, we considered the gene expressed in brain. In supplementary data we show relative expression as the mean RMA value in the region in which it was highest.
