ULBP2 and B-cell chronic lymphocytic leukemia: MICA was slightly upregulated on B cells from CLL patients compared with those from healthy donors, whereas high plasma levels of soluble NKG2D ligands (soluble MICA, MICB, and UL16 binding protein 2) were associated with poor treatment-free survival of CLL patients (59), suggesting that soluble NKG2D ligands may compromise NKG2D-mediated NK cell activation in CLL.