These conflicting results concerning TAM ligand expression in SS are also reflected in SLE where one study reported higher levels of Gas6 and lower Pros1 in the plasma of SLE patients [118], while other groups have detected decreased Gas6 in the plasma of SLE patients [119], or little difference in plasma Gas6 and Pros1 between controls and SLE patients [120]. Here, GAS6 is linked to synovial sarcoma.