In conclusion, the reduced percentages of PD-L1/PD-L2 positive APCs, together with altered concentrations of their soluble forms and correlations with gene expression in TT, suggest that dysregulation of the PD-1/PD-L1/PD-L2 pathway may impair the ability of the immune system to control endometrial cancer growth effectively. Here, PDCD1 is linked to endometrial cancer.