Recently, ELF4 has been linked with mucosal integrity, and deficiency of ELF4 has been identified in male patients with monogenic X‐linked diseases resembling inflammatory bowel disease and/or Behçet syndrome with oral and gastrointestinal ulcers, fever, dermatitis, arthritis, and elevated systemic markers of inflammation.129, 130. This evidence concerns the gene ELF4 and Arthritis.