The federal appeals court in San Francisco Monday upheld a decision by the U.S. Food and Drug Administration to approve the use of soy leghemoglobin as a color additive in Impossible’s imitation beef patties. The 2019 decision cleared a hurdle for Impossible to extend its burger sales from restaurants into grocery stores beginning that year.

Soy leghemoglobin, or “heme,” is a red, genetically modified ingredient that gives the Impossible Burger its meat-like flavor. Impossible has long touted its “heme” as the key to its meat-like flavor, but its use has meant additional regulatory hurdles and challenges in the U.S. and has kept doors to major markets, including China and the European Union, closed. Beyond Meat, its primary competitor, often points to its GMO-free ingredient list in its marketing.

The market for plant-based meat is forecast to grow to $450 billion and make up a quarter of the $1.8 trillion meat market by 2040, according to consulting firm Kearney, which also sees animal protein peaking in 2025.

The Center for Food Safety didn’t immediately respond to an email on the ruling.

Read More: America’s Biggest Meat Company Gives Faux Burgers Another Shot

In its ruling, the court denied the Center for Food Safety’s request to overturn the FDA decision. Two judges said the FDA applied the correct standard in reviewing the safety of soy leghemoglobin and that the agency’s decision was supported by “substantial evidence.” They also said the FDA could rely on a study commissioned by Impossible.

The third judge declined to consider whether CFS had raised valid concerns, saying the group lacked standing to challenge the FDA ruling.

The case is Center for Food Safety v. FDA, 20-70747, U.S. Court of Appeals, Ninth Circuit (San Francisco).