This is very different compared with myeloma patients in which PD-1 expression increased in BM anergic Vγ9Vδ2 T cells after ZA stimulation, suggesting that these cells are intrinsically programmed to increase their threshold of refractoriness to pAg-induced TCR stimulation via PD-1 upregulation (30). The gene discussed is PDCD1; the disease is plasma cell myeloma.