CD80 and B-cell chronic lymphocytic leukemia: In addition, CBIs have been reported to increase the expression of various immune surface markers such as NK-cell activating ligands MICA and PVR/CD155 in multiple myeloma cells [26], and T-cell co-stimulatory molecules CD80 (B7-1) and CD86 (B7-2) in leukemic B cells of chronic lymphocytic leukemia (CLL) [27].