Knockdown of STAT5 reduces CFC and LTC-IC frequencies of CB CD34⁺ cells. (A) CFU-GM and BFU-E assays with control and STAT5-transduced CB cells. Assays were performed 3 times in duplicate under conditions indicated in “CFC, CFU-GM, BFU-E, and LTC-IC assays.” Error bars denote standard deviations. (B) Limiting-dilution CFC assay performed as described in “CFC, CFU-FM, BFU-E, and LTC-IC assays.” Poisson statistics were used to calculate CFC progenitor frequencies. N = 3; a representative experiment is shown. (C) Percentage of CFC progenitors as calculated from the limiting-dilution assays. The average of 3 experiments is shown, with error bars representing standard deviations. A Student t test was performed to calculate statistical differences between the 2 groups. (D) Limiting-dilution LTC-IC assay performed as described in “CFC, CFU-GM, BFU-E, and LTC-IC assays.” Poisson statistics were used to calculate LTC-IC frequencies. N = 3; a representative experiment is shown. (E) The average percentage of LTC-IC cells as calculated from the limiting-dilution experiment shown in D. N = 3; error bars denote standard errors.