FIGURE 2

Dual expression (tumor cells and macrophages) of oncostatin M (OSM) in cutaneous squamous neoplasms. A, keratoacanthoma (KA) showing moderately intense cytoplasmic OSM immunoreactivity. Note the absence of OSM-positive macrophages in this field of the KA. B, squamous cell carcinomas exhibit a higher mean level of tumor-associated OSM-labeled macrophages and less frequent and faint OSM labeling of tumor cells as compared with KA. C, another example of a squamous cell carcinoma with no tumor labeling and numerous peritumoral macrophages.