**8. Significance of somatic microenvironment 'Niche' on VSELs functionality**

A relatively quiescent VSEL and actively dividing progenitor model that possibly exists in ovary, testis, bone marrow, cord blood and Wharton's jelly ensures that the 'master stem cell' undergoes very few rounds of DNA replication to prevent its genome from age-related changes and acquisition of errors during DNA replication.

Table 3 highlights the importance of the somatic niche in controlling the stem cell fate. It is the same VSEL that exists in different body organs but the niche dictates its fate [46].


**Table 3.** Details of Very Small Embryonic-Like Stem Cell–Derived Progenitors in Adult Human Tissues

The possible reason why extensive plasticity of VSELs is evident in bone marrow and cord blood (so many different kind of TCSCs have been described) in contrast to testis or ovary may be because the bone marrow niche is more permissive as compared to a 'gonadal' niche which is more specialized and thus restricted in nature.
