A more than 100-kb stretch of the genome is located in chromosome 3q13.33 that includes ARHGAP31, TMEM39A, POGLUT1, TIMMDC1, and CD80. In addition to the present study on the Japanese population, this locus, as represented by top-hit SNP rs2293370, has been reported as a susceptibility region to PBC in European and Chinese populations10,14,17. The gene discussed is CD80; the disease is primary biliary cholangitis.