A method for treating a condition, comprising administering to a subject in need thereof a composition that contains somatic stem cells that are 2 to less than 6 micrometers in size and Lgr5+, wherein the condition is selected from the group consisting of neurodegenerative disorder, muscle-degenerative disease, cancer, metabolic disorder, autoimmune disorder, inflammatory disorder, heart disorder, circulatory disorder, a condition associated with aging, and damaged tissue.L'invention concerne une cellule souche isolée somatique dont la taille va de 2 à moins de 6 µm et Lgr5+. Elle indique aussi des procédés de préparation et d'utilisation des cellules.