Is this a way for cells growing in the form of attached communities to achieve greater tolerance to oxidative stress or to various antimicrobials? What are the molecular bases for this contact-dependent behavior? The design of specific short-lifetime genetic reporters, to be monitored in our multiparametric dispersed surface approach, will undoubtedly help to answer these questions. Oligodendrocytes are generated from oligodendroglial progenitor cells which proliferate in the subventricular zone and migrate to formative white matter regions, where they further proliferate, differentiate, and form myelin sheaths around axons. Migration of OPCs is an essential step not only during the early stage of oligodendrocyte lineage cells development but also in some demyelination pathological conditions such as Multiple Sclerosis and other variety of CNS injuries. Adult stem cells are rare, premature cells capable of self-renewal and RHPS 4 methosulfate generating distinct differentiated cell types within a tissue. There is no doubt that identification and isolation of stem cells have potentially important implications not only for regenerative medicine but for understanding of pathogenesis of a variety of diseases. The existence of stem cells in adult human thyroid tissue has been suggested by several studies. Based on immunohistochemical analyses, two PSB 36 groups proposed that p63-positive cells residing in solid cell nests may be undifferentiated stem cells and undergo follicular maturation. Thomas et al. found that a small subset of cells in nodular goiters express a stem cell marker Oct-4 and endodermal markers GATA-4 and HNF4a using RT-PCR, immunohistochemistry and flow cytometry; however, no functional characterization was performed. The subsequent work by the same group reported that possible stem cells were isolated from nodular goiters using a sphere formation approach in a serum-free medium containing epidermal growth factor and basic fibroblast growth factor, and some functional studies were performed. This method has been frequently used to isolate stem cells from several other tissues. The obtained sphere cells did not express thyroid specific genes such as thyroglobulin and TSH receptor, but their expressions emerged in monolayer culture stimulated by serum and TSH. However, the growth potential of the cells was very limited: the proliferation stopped after 4�C5 days of culture. More recently, Fierabracci et al. have also reported the identification of stem/progenitor cells in normal human thyroid tissues.