Cryo-electron microscopy investigations have revealed that NPRA is an ornithine homodimer composed of a central Broad-complex, Tramtrack, and Bric-à-brac (BTB) structural domain, along with a BTB domain and carboxy-terminal Kelch helical bundles, and that NPRA is extensively distributed in multiple tissues, such as blood vessels, the heart, kidneys, lungs, adrenal glands, and adipose tissue, testes, liver, and immune system, as well as in certain cancers. The gene discussed is NPR1; the disease is cancer.