For example, decrease of TRAIL-R2 on CD8 T cells was reported in severe aplastic anemia (74), conversely, in rheumatoid arthritis TRAIL and its receptors (both death and decoy) were increased in both CD4 and CD8 T cells compared to control individuals, and the variation of TRAIL-R1 on CD8 T cells correlated with the disease activity (75). Here, CD4 is linked to aplastic anemia.