IDO1 and juvenile polyposis syndrome: Additionally, the mean concentrations of all 14 immunoregulatory markers (sCTLA-4, sPD-1, sPD-L1, sPD-L2, sTIM-3, sLAG-3, sBTLA, sHVEM, IDO, sCD28, sCD80, sCD27, sGITR, and sCD137) were higher in PJI patients compared to TJA patients.