Peng et al. [53] investigated the clinical significance of sPD-1 and other soluble immune checkpoint markers, including sTIM-3, sCD137, sCD27, sLAG-3, sIDO, sPD-L2, sCD152, and sCD8 in NSCLC and reported increased serum levels of all examined biomarkers (including sPD-1) in patients with advanced-stage disease versus controls; nevertheless, sPD-1 was the only marker that failed to confirm its diagnostic value in subsequent ROC analysis while a higher diagnostic accuracy was reached when a combined detection assay of sTIM-3, sLAG-3, and sCD137 was performed [53]. Here, LAG3 is linked to non-small cell lung carcinoma.