GPR34 is deregulated by the t(X;14) translocation and is elevated in lymphoma tissue. (A) qPCR for GPR34, GPR82 and CASK from mRNA isolated from the t(X;14) specimen or CD19⁺ B cells from peripheral blood (PBL; n = 2), bone marrow (BM; n = 2), or spleen (Spl; n = 3) from healthy donors. Relative concentrations of GPR34 (GPR34/GAPDH) are expressed in copies/μL. (B) qPCR for GPR34 in MALT (n = 35), NMZBCL (n = 21), SMZBCL (n = 33), LPL (n = 23), DLBCL (n = 9), FL (n = 10), and MCL (n = 10) lymphomas, and normal resting (n = 11) or activated (n = 6) CD19⁺ B cells from peripheral blood or bone marrow (n = 5), resting and activated CD3⁺ T cells (n = 6) and CD14⁺ monocytes (n = 6). Analyses shown are the average of 2 independent experiments for each sample. *Compared with normal resting B cells, MALT (P = .03), LPL (P = .0006), NMZBCL (P = .0007), and SMZBCL (P = .001) had significantly higher GPR34 expression. (C) GPR34 gene expression analysis in lymphoma and brain tumor tissue; MALT (n = 24), NMZBCL (n = 24), SMZBCL (n = 28), LPL (n = 24), ABC DLBCL (n = 74), GCB DLBCL (n = 71), PBMCL (n = 31), normal LN (n = 8), naive B cells (n = 2), memory B cells (n = 2), glioma (n = 21), brain cell lines (n = 12), and normal brain (n = 3). (D) GPR34 expression on CD19⁺ tumor cells from MALT or SMZBCL biopsies, normal blood lymphocytes, and JeKo-1 lymphoma B cells. Expression of GPR34 is shown in the open histogram, isotype control in the gray histogram.