all three genotypes were seen. To enrich the microarray data for abundant and strongly-hybridized transcripts, we calculated the variance of each probe and excluded the lowest 50% from our analyses. Microarray data were ranked and normalized to mean 0 and variance 1/3 across each gene, the default for the Gene Recommender algorithm. SNP r2 values were calculated with 'snpMatrix.' Because all 52 samples were from a single county in Norway [27], we did not perform any adjustments for population stratification.
