Functionally, the Fab regions are responsiblefor their intriguing selectivity toward tumor antigens or receptors;following the binding, mAbs interfere and block the associated downstreamsignaling pathways.5 Among tumor antigens,programmed cell death protein 1 (PD1), CD20, and human epidermal growthfactor receptor 2 (HER2) are chief players and most widely investigated.3,6. Here, PDCD1 is linked to neoplasm.