Inclusion Criteria:  Patients starting anti-PD1 immunotherapy as part of marketing authorization alone or in combination (melanoma, clear cell renal cancer, urothelial carcinomas of the bladder, squamous cell carcinomas of the head and neck and non-small cell lung cancer). No contraindications to immunotherapy Non-pregnant patient Patient not opposed to participation in this study  Exclusion Criteria:  HIV seropositivity Patient with psychiatric or other conditions that may compromise his or her ability to give non opposition or to follow study procedures