Stimulation of endothelial cells by CCL2 increases cell permeability of the endothelial wall and tumor cell extravasation by signaling via Janus kinase 2 (JAK2), which triggers downstream signal transducer and activator of transcription 5 (Stat5) and p38 mitogen-activated protein kinase (p38MAPK) activation (Wolf et al., 2012). Here, JAK2 is linked to neoplasm.