Presence of hematopoietic CD45⁺ and CD45⁺/Sca-1⁺ cells in the adipose tissue as potential HSPCs. Epididymal adipose tissues (nonperfused) from 8-week-old mice were whole-mounted, and PECAM-1⁺ blood vessels (red or blue), CD45⁺ cells (green), and Sca-1⁺ cells (red) were visualized by double and triple immunofluorescence staining. Two representative examples are shown. (A) Abundant CD45⁺ cells are clustered in the tip region of the adipose tissue, and CD45⁺ cells are sparsely distributed in the body region of the adipose tissue. A portion of the clustered CD45⁺ cells is localized in the avascular regions, which are demarcated by yellow lines. Occasionally, a group of CD45⁺ cells is located inside the blood vessels (arrows). (B) Approximately 16% of CD45⁺ cells are Sca-1⁺ cells in the tip region of the adipose tissue. Scale bars, 100 μm.