The present invention relates to a method for identifying CD8+ Treg cells suitable for use as starting material in cellular immunotherapy, the method comprising i) analysing samples from target tissue A to identify CD8+ Treg cells with migratory character between the diseased tissue, collecting lymphatics, peripheral blood, distinct tissue adjacent to the diseased target tissue A and/or distinct tissue that is not vicinal though has migratory Treg communication with target tissue A, v) analysing samples from peripheral blood, tissue C, to identify CD8+ Treg cells with migratory character and/or functional character where the Treg cells are also emigrant from target tissue A, vi) analysing sample(s) from tissue compartments A and/or B and C, that are analytically or physically depleted of emigrants from thymus and/or immigrants from peripheral blood to a lymph node, to restrict analyses to CD8+ Treg cells of target tissue A origin and/or tropism, to identify emigrant CD8+ Treg cell populations of target tissue A, to identify emigrant CD8+ Treg cell populations with propensity to immigrate to target tissue A, to identify a migratory and/or functional defect in the CD8+ Treg cell population identified as expressing migratory and/or functional elements specific for target tissue A in any of tissue A, B or C, and whereby a combination of surface or intracellular markers on CD8+ Treg cells is identified, which combination identifies which surface or intracellular markers should be present and which surface markers should not be present in CD8+ Treg cell populations suitable for use as starting material in cellular immunotherapy.La présente invention concerne un procédé d'identification de lymphocytes Treg CD8+ appropriés pour être utilisés comme matériel de départ dans une immunothérapie cellulaire, ledit procédé consistant à i) analyser des échantillons de tissus cibles A afin d'identifier les lymphocytes Treg CD8+ à caractère migratoire parmi les tissus malades, à colle