Fig. 1From: PDGF-AA mediates mesenchymal stromal cell chemotaxis to the head and neck squamous cell carcinoma tumor microenvironmentMSCs reside in the OPSCC (human tonsil) tumor stromal microenvironment. The black arrows denote the tumor microenvironment (TM). Representative immunohistological sections of human OPSCC demonstrates the presence of a distinct population of gremlin-1+ MSCs in the TM (a–c). The black square denotes areas viewed at higher magnification. Cells positive for the myofibroblast/CAF marker, α-SMA+ , were also present within the TM (d–f). A small population of CD14+ lymphocytes are seen at higher power magnification, representing cells of hematopoietic lineage (g–i). The above photomicrographs are serial sections (4 μm thickness)Back to article page