HLA-DR52 is an HLA-DR serotype that recognizes gene products of HLA-DRB3 locus. Three allele groups can produce 35 isoforms. DRB3, DRB4, and DRB5 are minor DR beta-encoding loci, and they have been recognized as having distinct evolution, having diverged from DRB1 around 4 million years ago. The DRB3 locus is only apparent in a small subset of DR haplotypes, and most individuals lack DRB3.