HLA-G and B-cell chronic lymphocytic leukemia: Interestingly, Rizzo et al. have shown that in CLL, there is a significant correlation between the del/del HLA-G genotype and increased plasma levels of soluble HLA-G, but not between this genotype and increased membrane HLA-G levels, probably because of the instability of membrane HLA-G forms which are rapidly released into the plasma [181].