Midkine (MDK) is a ~15 kDa protein. Secreted protein that functions as a cytokine and growth factor and mediates its signal through cell-surface proteoglycan and non-proteoglycan receptors. Binds cell-surface proteoglycan receptors via their chondroitin sulfate (CS) groups. Thereby regulates many processes like inflammatory response, cell proliferation, cell adhesion, cell growth, cell survival, tissue regeneration, cell differentiation and cell migration. Participates in inflammatory processes by exerting two different activities. Firstly, mediates neutrophils and macrophages recruitment to the sites of inflammation both by direct action by cooperating namely with ITGB2 via LRP1 and by inducing chemokine expression. 1. Ichihara-Tanaka, K. et al. (2006) The Journal of biological chemistry 281, 30857-64. PMID: 169019072. Zou, P. et al. (2006) Journal of neurochemistry 99, 1470-9. PMID: 172306383. Horiba, M. et al. (2000) The Journal of clinical investigation 105, 489-95. PMID: 106833784. Ochiai, K. et al. (2004) Liver international : official journal of the International Association for the Study of the Liver 24, 484-91. PMID: 154823475. Kawai, H. et al. (2004) The American journal of pathology 165, 1603-12. PMID: 155095307. Takenaka, H. et al. (2009) American journal of physiology. Heart and circulatory physiology 296, H462-9. PMID: 190601269. Haffner-Luntzer, M. et al. (2014) PloS one 9, e116282. PMID: 25551381 | 
