PTGDR2 and medical procedure: To investigate the role of helper ILCs (hILCs) in the acute rejection after LT, we performed a comparative analysis of hILCs (CD45+Lin-CD127+) and the distinct subgroups, including ILC1s (CD45+Lin-CD127+CRTH2-CD117-), ILC2s (CD45+Lin-CD127+ CRTH2+), and ILC3s (CD45+Lin-CD127+ CRTH2-CD117+) in the peripheral blood of liver transplant recipients and healthy controls (Figure 1A).