Absence of mKng1-derived HK mRNA from the liver of mKng1^−/− mice. RNA was isolated from liver, kidney, adrenal, and lung of wild-type and mKng1^−/− mice as described in “Methods,” and analyzed by RT-PCR. Arrows depict mKng1- and mKng2-derived HK RT-PCR products. GAPDH mRNA was also analyzed by RT-PCR to ensure equal amounts of DNA were added to the reaction mixtures.