Stem cells, the detection of which is regarded as one of the main discoveries of the 20th century, express new genes of development, signaling pathways and receptor cell-to-cell interactions, controlling cell growth, migration and differentiation, tissue and organ formation. Embryonal stem cells opened the way to laboratory production of main parenchy mal and mesenchymal cells avoiding fertilization, gastrula and organogenesis. ESC culture allowed observation and elucidation of the phenomena and mechanisms of embryonic induction. Besides ESC researchers are interested in the study of heterogenous mesenchymal stem cells, which are highly plastic to adaptive differentiation and reprogramming. Molecular cell diagnostics of MSC "aging" is essential for early detection of many age-related diseases (atherosclerosis, cardiosclerosis, interstitial pulmonary fibrosis, liver and kidney cirrhosis etc.).