Current survey demonstrated the correlation between the histologic stage of PBC (II and III) and absolute counts of several peripheral blood subpopulations: CD4+CD25+FOXP3+ Treg cells, (CD3+/CD16+CD56+) NKT-like cells, CD3+ T lymphocytes and CD4+CD3+ cells. The gene discussed is FOXP3; the disease is primary biliary cholangitis.