Calcineurin inhibitors (CCN) are the basis of immunosuppressive therapy in renal transplantation. Several mechanisms have been implicated to explain their pro-oncogenic properties. One related to an increase in VEGF expression seems particularly interesting in the study of renal cell carcinoma in the transplanted patient. Indeed, the physiopathology of kidney cancer has clearly been associated with an increase in the production of VEGF. Furthermore, some polymorphisms of the gene encoding VEGF have already been associated with the survival of patients with renal carcinoma and the circulating level of VEGF in the general population. The search for an association between the polymorphisms of the VEGF gene and renal carcinoma in renal transplant patients could thus identify patients whose risk of renal cell carcinoma (cRCC) post-transplantation is increased. If the involvement of certain polymorphisms in the development of cRCC was confirmed in this population, their research before the introduction of the immunosuppressive treatment would make it possible to direct the choice of treatment towards molecules without pro-oncogenic property in the Patients such as mTOR protein inhibitors (sirolimus, everolimus). This research project is therefore in line with the desire to move towards a more "personalized" medicine that could be beneficial for the patient.