...dMMR and/or MSI tumor status defined by:- Loss of MMR protein expression using immunohistochemistry with two (anti-MLH1 and anti-MSH2 or anti-MSH6, and anti-PMS2) or four (anti-MLH1, anti-MSH2, anti-MSH6, and anti-PMS2) antibodies, - and/or ≥ two instable markers by pentaplex polymerase chain reaction (BAT-25, BAT-26, NR-21, NR-24, and NR-27),NB: Agreement of the Sponsor (GERCOR) is mandatory to include the patient (the patient’s file will be verified to confirm MSI/dMMR status before inclusion [an anonymized fax] and confirmation of a patient’s allocation will be sent by mail to the Investigator within 24h), 8. ...