Figure 2. Genes clustered according to expression level in different culture conditions. The x-axis follows the order of Figure 1. Expression was compared to basal culture conditions (SF3 in the apical chamber and SF2 in the basal chamber). As indicated on the x-axis, cultures were supplemented with 2% fetal calf serum or rcSF3 replaced SF3. Data were transformed to allow high-expressing and low-expressing genes to be represented on the same graph. The p value from the statistical analysis and number of members for each cluster are indicated. Cluster memberships are listed in the Appendix 2. As summarized in Table 2, some gene clusters were affected by only serum or only rcSF3, but many clusters indicated interactions between these two stimuli.