Population-specific principle component analysis (PCA) of gene expression in intestinal tissue in order to check if fish from the contaminated sites group together. Farmed cod highlighted. Gene names, populations (C = Control, F = Farmed fish, L = Store Lungegårdsvann and O = Odda/Sørfjorden) and CF = Condition Factor are presented in the figure. PCA applied to the entire data set (component 1 and 2) model explaining r2 = 0.88 and predicting Q2 = 74% of the data variation. 95% confidence intervals. Centered data.