The effect of N-Ras* on EPO-independent erythropoiesis.

(A) Cumulative expansion of transduced erythroid cells (defined as GFP⁺, CD13⁻ cells by flow cytometric analysis; see “Materials and methods”). (B) Frequency of CD41 expression. Insets show representative data at day 6 (open histograms show nonspecific fluorescence). (C) Frequency of CD34 expression on transduced erythroid cells. (D) Cumulative expansion of transduced erythroid CD34⁺ cells. Insets show representative data at day 6. Error bars represent SD (n > 5);P < .05, **P < .01.