The B cell receptor signalling pathway is represented by 10 genes: CD19, CD79b, SYK, CD72, BTK, NFATC1, VAV1, FCGR2B, FOS/AP-1 and BCAP. These data clearly demonstrate that KIS-1 DLBCL cells lack gene expression characteristic of PAX5-expressing B cells like RAJI, despite having an elevated level of PAX5 expression. Here, BTK is linked to diffuse large B-cell lymphoma.