Pituitary tumours are the second most common type of intracranial tumours in adults. Although these tumours can develop at any age, their incidence is thought to be higher in people over the age of 65. The role of cellular aging and immunosenescence (i.e., qualitative and quantitative aging of the immune system) has been highlighted in many endocrine and cancerous diseases. Paradoxically, the involvement of these mechanisms and the processes with which they are associated (hormonal variations, “inflammaging,” alterations in the tissue microenvironment) remain poorly understood in pituitary tumorigenesis. The PhD project will aim at studying the involvement of cellular and tissue aging of the mouse pituitary gland in tumour initiation and progression processes.