To explore whether tumor-released mesothelin could bind to macrophages, frozen cells isolated from human ascites (n = 6) or from solid tumors (n = 8) of ovarian cancer patients, as well as healthy donor monocytes (n = 12), were stained with anti-Epcam, anti-CD45, anti-CD14, anti-CD206, anti-mesothelin (K1) mAbs and 7-AAD. Here, MSLN is linked to ovarian cancer.