Ingenuity Pathway Analysis (IPA 7.1) was applied to genes that showed coordinate up- or downregulation during juvenile growth in multiple organs of mice and rats and also persistent changes in expression during aging (P < 0.05) in liver (hatched bars), kidney (solid grey bars), or lung (solid black bars). The 5 most overrepresented molecular, cellular, or physiological functions are shown. Cell cycle, DNA replication, and cellular growth and proliferation were amongst the most overrepresented functions in kidney and lung, suggesting that genes implicated in postnatal growth that continue to decline during aging were involved in cell proliferation.