The identification of the extracellular calcium sensing receptor (CaSR) was a crucial step in understanding nutrient sensing in mammals. In mammalian organisms the CaSR has multiple roles: besides calcium homeostasis, it is involved in protection against osteoporosis, blood vessel calcification, prevention against colorectal cancer, is involved in metastasis of breast and prostate cancer cells to bone. The proposed ITN will perform basic and multidisciplinary investigations into the role of the CaSR and will provide experimental data for computational modelling. It will use holistic approaches of systems biology to gain knowledge on mechanisms of CaSR function.We will use intersectoral expertise in revealing the significance of CaSR signalling in cancer, and cardiovascular disease.The purpose of this ITN is to:• Educate and train Early Stage Researchers to become excellent scientists, enable them to gain a holistic view of their specific research area, prepare them for the challenges of working in a highly competitive environment, be it in Academia or in Industry.• Generate a systems biology model for CaSR-dependent signalling in order to find innovative therapeutic approaches and interventions for the natural and synthetic ligands of the CaSR.• Establish long lasting interdisciplinary and intersectoral cooperation among basic, clinical and applied researchers, working on the CaSR to strengthen the European Research Area.Being in a research environment that examines the role of one single molecule in many different tissues (e.g. kidney, intestine, blood vessels) and pathologies (cancer and vascular calcification), will increase the awareness of the young researchers for a holistic approach in understanding CaSR-related pathophysiology. Continuous comparison of the function of the CaSR in systems studied by their fellow ESRs, will sensitize the young researchers for the complexities of biomedical research and advantages of multidisciplinarity.