Lower (absent) expression levels of co-stimulatory molecules (CD40, CD80, CD86) on MSPCs of patients with MDS or AML [483] and higher levels of immunosuppressive cytokines (TGFβ, IL6, HGF) may explain the altered immunosuppressive capacity of MDS/AML-MSPCs [483,519]. Here, CD86 is linked to acute myeloid leukemia.