ENTPD1 and AL amyloidosis: In both myeloid leukemia and multiple myeloma, using flow cytometry, the bone marrow resident γδ T cells, a T cell subpopulation of non-MHC-restricted, have shown TIGIT, PD-1, TIM3, and the ectonucleoside triphosphate diphosphohydrolase-1 (CD39) co-expression at a high level compared to αβ T cell but similar to that expressed on CD8+ effector T cells (139).