However, to the best of our knowledge, nobody hitherto compared in parallel the expression of PD-L1 on M-MDSCs, MO/MA, tumour cells (TC), tumour-infiltrating immune/inflammatory cells (IC) and the profile of sPD-L1 in different TMEs of ovarian cancer in the context of their clinical significance. The gene discussed is SPDL1; the disease is ovarian cancer.