FIG. 4.

Hierarchical clustering analyses of interindividual differences and treatment regimens of primary human hepatocyte samples. Total RNA was isolated from cultures of primary human hepatocytes from five different donors −/+ Matrigel overlay. RNA transcript profiles were analyzed by microarray hybridizations, as described in “Materials and Methods” section. Results were hierarchically clustered (ArrayAssist, Stratagene) before (A) and after (B) filtering for twofold changes in gene expression level between Matrigel-treated samples and untreated controls.