The human germinal center-associate lymphoma (hGAL) protein, also known as the germinal center expressed transcript-2 (GCET2) gene, is located on chromosome 3q13.3, encoding for a 178 amino acid protein. GCET2 is an ortholog to a mouse germinal center (GC)-expressed transcript, M17. GCET2 is highly expressed in the normal GC with moderate expression in the thymus and spleen. HGAL protein is localized in the cytoplasm, and expressed in GC in normal lymphoid tissue and in GC-derived lymphomas. Expression of GCET2 mRNA was one of the top 10 candidate molecules that predicted improved survival and an independent positive prognostic factor in patients with diffuse large B-cell lymphoma (DLBCL).

HGAL staining is also present in 100% of Burkitt lymphomas, 97.6% of follicular lymphomas, 87.5% of mediastinal large B-cell lymphomas and 68% of DLBCLs. HGAL was demonstrated to be more frequently positive in follicular lymphomas, superior to Bcl-6 and CD10 staining. Through gene expression profiling, DLBCL are classified further into two additional subgroups: GC B-cell like and activate B-cell like DLBCL that cannot be reliably distinguished by morphology. Addition of hGAL to the Hans, Choi, and Tally immunohistological algorithms has been shown to improve the detection of the GC B-cell like subgroup.