The brief itself acknowledges that recent legal precedent and government policy allow for genes to be patented, but there is an older precedent (as of now, part of my signature text) that products of nature, rather than of human ingenuity, have no place in the patent system.
It warms my heart that one small step has been taken, and I hope this trend continues.
"the qualities of these bacteria, like the heat of the sun, electricity, or the qualities of metals, are part of the storehouse of knowledge of all men. They are manifestations of the laws of nature, free to all men and reserved exclusively to none." SCOTUS, Funk Bros. Seed Co. v. Kale Inoculant Co.