It has been well established that ERK1/2 signaling, often subdivided into nine types of pathways, can regulate the hepatocyte proliferative response during liver regeneration. However, the effect of ERK1/2 signaling on the proliferation of other hepatic cell types remains unclear. We isolated and purified 8 liver cell types at 10 time points after 2/3 hepatectomy in adult rats. For each cell type, mRNA expression changes for ERK1/2 signaling-involved genes were monitored up to 168 h, using microarrays. Real-time PCR assays were performed for array data verification.