MKI67 and rheumatoid arthritis: Furthermore, a German case-control study assessed several genes [39], revealing nine of them associated with lung involvement in RA: arginase 1 (ARG1), thymidylate synthetase (TYMS), sortilin 1 (SORT1), Ki-67 proliferation marker (MKI67), olfactomedin 4 (OLFM4), baculoviral inhibitor of apoptosis repeat containing 5 (BIRC5), membrane spanning 4 A4A domains (MS4A4A), C-type lectin domain family 12 member A (CLEC12A), and the long intergenic non-protein coding RNA (LINC02967).