Higher levels of carbohydrate antigen 15–3 (CA15-3) and carbohydrate antigen-125 (CA125) were observed in RA-ILD (P = 0.01 and 0.03 respectively), levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19–9 (CA19–9) did not differ significantly (P = 0.47 and 0.19 respectively). This evidence concerns the gene CEACAM5 and rheumatoid arthritis.