PDCD1 and neoplasm: The relevance of the immunosuppressive activity of this cytokine in tumours has been conducive to the development of several small molecules, peptides, antisense oligonucleotides, cytokine traps and antibodies to block the TGF-β pathway in cancer.98 Although their efficacy as monotherapy agents has been disappointing, their activity in combination with anti-PD-1 or anti-PD-L1 agents has renewed interest in inhibitors tackling the functions of this cytokine.