Given the toxicity challenges associated with selective iNOS inhibitors and our interest in understanding the mechanism of action of traditional Chinese medicines (TCMs) that have been used successfully to treat patients with RA who do not respond to disease-modifying antirheumatic drugs [42–46], we performed a drug screen in zebrafish to identify TCM-derived small molecules based on their ability to stimulate lymphatic vessel growth (data not shown). The gene discussed is NOS2; the disease is rheumatoid arthritis.