To determine if TSPY protein/fragments could be located on the cell surface [55–58, 62], we had conducted a flow cytometry analysis of the human HCC tumor HuH7 cells, which do not harbor a Y chromosome nor TSPY gene [63], transfected with either a TSPY gene or control vector alone, representing TSPY-positive and negative tumor cells respectively. Here, TSPY1 is linked to hepatocellular carcinoma.