Proliferative response of UT-7/TPO cells to JTZ-132. UT-7/TPO cells were deprived of rhTPO overnight and then plated at a density of 1 × 104cells/well in IMDM containing 10% FCS and incubated in the presence of JTZ-132 or rhTPO. After 3 days, the absorbance was measured by the WST-1 assay in duplicate. Each value is calculated as a percentage of that induced by maximal rhTPO (100 ng/mL) or rhEPO (1 IU/mL) response. Data shown are the mean ± SEM of 3 independent experiments in UT-7/TPO cells and single experiment in UT-7/EPO cells.