The data in this study showed an association between low serum levels of osteocalcin and MAP infection, regardless of disease status, as shown in Figure 1B. This was further confirmed when the serum level of osteocalcin was lower in blood samples from MAP positive controls (patients who appear to be free from CD or RA), indicating that infection by intracellular pathogens such as MAP directly impact the osteocalcin production mechanism. Here, BGLAP is linked to rheumatoid arthritis.