Weber M, et al. - Authors examined the data to study if the alterations of PD-L1 and PD-L2 expression in blood of oral squamous cell carcinoma (OSCC) cases were correlated with survival and also to comprehend if it could serve as an immune monitoring parameter. Using RT-qPCR, they evaluated PD-L2 mRNA expression in tumors and healthy oral mucosa specimens and also in corresponding peripheral blood samples of 48 OSCC cases and 26 healthy controls. They noticed higher PD-L2 expression in OSCC candidates as compared to healthy controls. They found an association of PD-L2 expression above the cutoff point (COP) (positive) with malignancy. They suggested peripheral blood PD-L1 expression, a relevant prognostic marker, and also a feasible parameter to monitor immune dysfunction in malignant conditions.