In general, the lowest median concentrations of the markers were found in the control patients, whereas the highest were found in either AIF patients (sPD-1, sPD-L1, sPD-L2, sBTLA, sCD80, and sCD137) or PJI patients (sCTLA-4, sTIM-3, sLAG-3, sHVEM, IDO, sCD28, sCD27, and sGITR). Here, IDO1 is linked to juvenile polyposis syndrome.