We previously established a useful rat mAb (clone PMab-1) against a 14-residue peptide in the platelet aggregation-stimulating (PLAG) domain of mouse podoplanin.(15) Podoplanin is a type I transmembrane protein that is highly expressed in malignant cancer cells and is implicated in tumor-induced platelet aggregation.(16) In our another study, we developed the PA tag system with high affinity and specificity.(6) The PA tag is derived from the human podoplanin PLAG domain. This evidence concerns the gene PDPN and neoplasm.