Clonal genotypic patterns of erythroid and granulocytic progenitors from PMF patients. Detection of the MPL W515 mutations by direct sequencing. Histograms showing the percentages of MPL W515 100% mutated (■), 50% mutated (), and MPL WT (□) colonies from 3 PMF patients. BFU-E indicates burst-forming unit–erythroid; CFU-GM, colony-forming unit–granulocyte-macrophage; and n, the numbers of analyzed clones for each histogram bars.