Efzofitimod is a splice variant of histidyl-tRNA synthetase HARS1, created by fusing the immunomodulatory domain of HARS1 with the Fc segment of a human antibody. It targets neuropilin-2 (NRP2) and exhibits anti-inflammatory and immunomodulatory properties. Efzofitimod can downregulate both innate and adaptive immune responses in inflammatory disease conditions, helping to mitigate interstitial lung disease (ILD).