Described herein is a method of treating a disorder, the method comprising: administering to a subject in need thereof a composition that contains a population of somatic stem cells that are 0.3-6.0 micrometers in size and CD9+, CD349+, CD133−, CD90−, CD34−, SSEA1+, SSEA4+, CD13+, or Stro1+, wherein the disorder is selected from the group consisting of a neurodegenerative disease, nervous system disorder, cancer, metabolic disorder, autoimmune disorder, inflammatory disorder, heart or circulatory disorder, blood disorder, muscular dystrophy, gastrointestinal disease, kidney disease, liver disease, lung disease, adrenal disorder, a condition resulting from an injury, a condition associated with aging, and virus infection.