Scoring of BCL2 staining by pathologists. (A) The schema of the BCL2 IHC scoring based on the pattern, positive cell ratio, and intensity. *The staining intensity of all tumor cells. (B) Representative images of the BCL2 expression in DLBCLs. BCL2 protein expression by IHC in representative cases is shown at ×20 objective (left) and at ×40 objective (right). A BCL2 score of 3+ without a BCL2 rearrangement (a-b) and with a BCL2 rearrangement (c-d) by FISH analysis. Variable staining patterns of the cases with a BCL2 score 2+ (e-l). Note that compared with the score of 3+, the cytoplasmic staining intensity of the tumor cells was not uniformly strong. A BCL2 score of 1+ corresponded to negative staining in the majority of the tumor cells, and only weak positive staining in a small number of the tumor cells (m-n). A BCL2 score of 0 corresponded to only T-cell staining (o-p).