Although a small number of divergent individuals occurred within cluster 1 (Figure 3 ), significant overall variation in expression patterns occurred between cluster 1 and cluster 2 ( Figure 5 ). Most individuals in cluster 1 could be characterized by comparatively very elevated constitutive and LPS-stimulated TNF-a expression. Individuals in cluster 2 were characterized by relatively high levels of constitutive and LPS-stimulated expression of TLR4, TLR9 and FoxP3.