Association between gene expression and prion-related lesions in 4 CNS areas. Genes are classified in 7 groups according to their role in apoptotic pathways. P1: BAX, BAD, BAK, BCLXS, BCL2, BCLXL, MCL1, AIF, APAF1, PARP1 (mitochondrial pathway); P1a: BAX, BAD, BAK, BCLXS (pro-apoptotic Bcl-2 family factors); P1b: BCL2, BCLXL, MCL1 (anti-apoptotic Bcl-2 family factors); P1c: AIF, APAF1, PARP1 (other apoptosis factors); P2: FAS, FASL, TNFA, TNFR1, TNFR2, TGFB (extrinsic pathway); P2a: FAS, TNFR1, TNFR2 (receptors); P2b: FASL, TNFA, TGFB (ligands). Lesions: Pr (prion deposition); Sp (neuropil spongiosis); Vac (neuronal vacuolisation) and Ag (astrogliosis). PC: percentage of the variability explained by the first principal component of each group. Significant P-values (P < 0.05) obtained using a stepwise regression between the first principal component of each group and the lesions are shown. (ns: not statistically significant).