spleen marginal zone morphology trait macrophage morphology trait spleen marginal zone macrophage morphology trait Any measurable or observable characteristic related to the shape, structure, color, or pattern of the cells present in the splenic marginal zone that are involved in the recognition and clearance of material, such as pathogen-derived material, from the splenic circulation. Spleen marginal zone macrophage cells express the cell surface protein CD209b (also called Signr1), which is often detected with the ER-TR9 antibody. VT:0008240 splenic marginal zone macrophage morphology trait Trait.ontology ER-TR9 positive cell morphology trait