Importance of thrombopoietin (TPO) and its receptor (MPL) in deficient mice

Platelet counts in mice that were homozygous deficient (-/-), heterozygous deficient (+/-), or wild-type (+/+) for the thrombopoietin gene (TPO) or the thrombopoietin receptor, c-Mpl (MPL). The platelet count is 10 to 20 percent of normal in homozygous TPO or c-Mpl-deficient mice and 65 percent of normal in heterozygous TPO-deficient mice.