To understand a possible mechanism that could mediate the mobilization of Treg from BM, we studied the expression of S1P1 on Treg (S1P1 antibody staining was tested on HTC Rat hepatoma cell line over expressing human S1P1 prior to staining on antigen-specific Treg in BM and PB—Supplementary Fig. 3). The gene discussed is S1PR1; the disease is hepatocellular carcinoma.