In addition, IL-33 elevated the immunohistochemistry (IHC) staining intensity of endothelial cell marker like CD31, an indicator of neomicrovessels (i.e. blood and lymphatic vessels), which suggested that active angiogenesis and lymphangiogenesis occurred in IL-33-treated tumours (Fig. 4h). The gene discussed is PECAM1; the disease is neoplasm.