Bone marrow–and HSC-derived ECs are detected in multiple tissues. (A) GFP⁺ (green) KSL-derived CD31⁺ (red) cell (arrow) and a GFP⁺, VWF⁺ (red) cell (insert) in skeletal muscle. (B) GFP⁺ BM-derived CD31⁺ cells in lung (arrow; insert: high magnification; A indicates alveolus, L indicates vascular lumen). (C) GFP⁺ BM-derived CD31⁺ cells in the distal small intestine. Donor-derived gut-associated lymphatic tissue is indicated (arrowheads) and a cross-section of a GFP⁺ CD31⁺ vessel is shown (arrow; insert: high magnification of neighboring GFP⁺ vessel). (D) GFP⁺ KSL-derived VWF⁺ cells in ventricular free wall of the heart (arrow; insert: higher magnification; V indicates ventricular cavity). (A,D, 2000 KSL cells; B-C, 10⁶ BM. A-B, DAPI nuclear stain (blue). Scale bars: A, 10 μm; B, 20 μm; C, 25 μm; and D, 10 μm.) Original magnifications: × 40 (A,C inserts); × 60 (B,D inserts).