CD70 expression of AML cell lines and primary bone marrow samples from patients with AML. (A) Evaluation of CD70 expression in several primary AML cell lines by flow cytometry. (B) Representative images of immunohistochemical staining for CD70 expression of bone marrow samples derived from patients without AML (normal bone marrow) and patients with newly diagnosed AML. Leukemic blasts in patients with AML were identified by their morphology. (C) Comparison of CD70 expression in bone marrow samples of 136 patients with AML and 8 individuals with normal bone marrow findings by immunohistochemical staining. The H-score was used to determine the staining intensity. ****P < .0001, by unpaired Student t test. (D) Analysis of CD70 expression in bone marrow samples of patients with newly diagnosed AML by flow cytometry. Percentage of CD70-expressing cells and median fluorescence intensity (MFI) of the CD70-positive cell population are depicted.