While the interaction markers PD‐L1 (Programmed cell death ligand‐1) and CD229 showed no differential expression between peripheral and core regions, the increase in CD84, CD150, and CD319 positive cells implicates a stronger communication of CLL cells with BMSCs and T cells in the core region (Figure 2B). This evidence concerns the gene LY9 and B-cell chronic lymphocytic leukemia.