Immunohistochemical expression. CD105 positive structures (brown) with endothelial cell morphology. Surrounding positive caldesmon staining (red) is seen in more mature blood vessels. The unbiased counting frame is illustrated. Countable structures inside the frame or in contact with the non-solid blue line, and without contact with the red exclusive line, were counted and in this case 7 structures were counted. (Original magnification x 200).