To investigate association heterogeneity due to ancestral differences, we revisited the previous data on trans-ancestral associations in high-density immune-loci genotyping-array (Immunochip) datasets (1 Korean and 7 European datasets) and genome-wide association study (GWAS) -derived imputed Immunochip datasets (1 Korean and 4 European datasets) that were generated from ACPA-positive RA cases and controls (n = 9,299 Koreans [2,234 cases and 7,065 controls] and n = 45,790 Europeans [10,288 cases and 35,502 controls])3. This evidence concerns the gene PRTN3 and rheumatoid arthritis.