Stromal cells of white adipose tissue (WAT) are organized in two layers, including a perivascular inner ring and peripheral supra-adventitial ring. Adipose stromal/progenitor cells (ASCs) are mainly localized in the supra-adventitial ring, and a current model suggests that ASCs could arise from pericytic progenitors in the perivascular inner ring. It was hypothesized that CD34−/CD146+ pericytes in the inner ring differentiate from inside out into ASCs in the supra-adventitial layer, which are CD34+, but do not express CD146 (CD34+/CD146−). Given the importance of CD34 as ASC marker as well as CD146 as a stem cell marker in bMSCs, it would be interesting to further characterize CD146 in cs-DLK1−/cs-CD34+ ASCs. The Zwerschke Group demonstrated the spatial localization of CD34+/CD146+ and CD34-/CD146+ cells in the adipose niche of subcutanous white adipose tissue and identified CD146 as an intracellular protein in human cs-DLK1-/cs-CD34+/cs-CD146- ASCs (Hörl S, Ejaz A, Ernst S, Mattesich M, Kaiser A, Jenewein B, Zwierzina ME, Hammerle S, Miggitsch C, Mitterberger-Vogt MC, Krautgasser C, Pierer G, Zwerschke W. CD146 (MCAM) in human cs-DLK1-/cs-CD34+ adipose stromal/progenitor cells. Stem Cell Res. 2017 May 17;22:1-12. doi: 10.1016/j.scr.2017.05.004. PubMed