TWSG1 expression in human erythropoiesis. (A) Microarray confirmation by quantitative PCR using erythroblasts from 6 separate donors (y-axis, copy number/ng total RNA). Each line associated values from the same donor on separate days. D7, culture day 7; D14, culture day 14. *P < .05. Bars represent the mean values. Flow cytometry analysis for CD71 and GPA surface expression on culture day 7 (B) and day 14 (C). Flow cytometric gates denoted as 1, 2, 3 (panel B) and 4, 5, 6 (panel C) were sorted for quantitative PCR quantitation of TWSG1. (D) TWSG1 expression level in the sorted populations according to the sorted gates shown in panels B and C.