The choice of treatment of patients with metastatic melanoma depends on the status of B-RAF of the tumor: in the absence of mutation, treatment with immunotherapy (currently anti-PD1) is proposed in the first line; When B-RAF is mutated, treatment with targeted therapies is retained: B-RAF and MEK inhibitors are prescribed in combination (vemurafenib + cobimetinib or dabrafenib + trametinib).

Patient response rates for targeted therapies range from 50 to 60%, and the occurrence of sometimes severe side effects is not predictable. There are currently no predictive biomarkers of patients' response to targeted therapy molecules. The in vitro evaluation of the intrinsic sensitivity of the cells of patients to different combinations of targeted therapy molecules would make it possible to propose the best therapeutic combinations. The cutaneous metastases are chosen in the model because of easy access to collect tumor tissue.

The most relevant in vitro models for mimicking cutaneous melanoma metastases are explant cultures and human skin equivalents.

Inclusion Criteria:

• Major Patients,
• patients with melanoma (stage IV) with cutaneous metastases,
• seronegative HIV, HBV, HCV, HTLV1.

Exclusion Criteria:

• Absence of cutaneous metastasis or in transit
• HIV or HBV or HCV or HTLV1 seropositivity
• Patient minor, patient under guardianship or curatorship