Expression of TLT-1 in splenic MKs and platelets. Frozen serial sections of murine spleen were fixed and stained with hematoxylin and eosin (A) or anti–TLT-1 followed by horseradish peroxidase–conjugated antirabbit antibody (B) or secondary antibody alone (C). (A-C) Magnification × 200. (D) Enlargement of the approximate area demarcated in panel B. MKs are marked by yellow arrows.