PTPN22 and pernicious anemia: A meta-analysis of a genome-wide association study involving 2166 patients with pernicious anemia and 659,516 individuals from population biobanks identified the following genes associated with pernicious anemia: Protein Tyrosine Phosphatase, Non-Receptor Type 22 (PTPN22), Polyribonucleotide Nucleotidyltransferase 1 (PNPT1), Major Histocompatibility Complex Class II (MHC II) DQ beta 1 haplotype (HLA-DQB1), Interleukin-2 Receptor Alpha Subunit (IL2RA), and AIRE [12].