Biotech CEOs have joined a growing list of business executives vocally opposing President Trump's assault on the Deferred Action for Childhood Arrivals program.

An open letter to Trump penned by Decibel Therapeutics CEO Steven Holtzman and Ovid Therapeutics (OVID CEO Jeremy Levin says that DACA participants, often dubbed "Dreamers," are key players in the life sciences sector. "Dreamers are vital to the future of our companies and our economy. With them, we grow and create jobs. They are part of why we will continue to have a global competitive advantage."

Trump's decision was announced by Attorney General Jeff Sessions, a noted immigration critic. It gave Congress six months to come up with a new immigration policy tied to the DACA program.

DACA was created by President Obama in 2012 via an executive order and gave children younger than 16 brought into the U.S. without documentation by their parents, rights to education and employment if they signed up for the program. Current DACA participants will be allowed to hold onto their status until their two-year permits expire.

The DACA program has given a safe status to almost 800,000 people but the Trump announcement means that deportation of those in the program could begin as early as March. The DACA program was denounced by Republicans as unconstitutional and created a wedge issue with conservatives looking to take a hardline stance on immigration and against Obama's use of an executive order.

The open letter points out that the DACA program has been successful. "All DACA recipients grew up in America, registered with our government, submitted to extensive background checks, and are diligently giving back to our communities and paying income taxes. More than 97 percent are in school or in the workforce, 5 percent started their own business, 65 percent have purchased a vehicle, and 16 percent have purchased their first home. At least 72 percent of the top 25 Fortune 500 companies count DACA recipients among their employees."

Holtzman and Levin also give a bottom line illustration of the impact of doing away with the DACA program. "Our economy would lose $460.3 billion from the national GDP and $24.6 billion in Social Security and Medicare tax contributions."

The letter prompted a parade of life science executives as well as investors to sign onto the document urging President Trump to reverse his decision and preserve the DACA program. Among the executives signing onto the letter were CEOs from Seattle Genetics (SGEN - Get Report) , Juno Therapeutics (JUNO and Nimbus Therapeutics Inc. Partners in investment firms Kleiner Perkins Caufield & Byers, Atlas Venture and BVF Partners also joined the chorus.

The biotech open letter added volume to corporate opposition to the Trump administration's DACA decision. More than 400 business leaders signed on to a different letter calling on the White House to reverse its position. Those leaders included CEOs from Microsoft (MSFT - Get Report) , JPMorgan Chase (JPM - Get Report) , Google (GOOGL - Get Report) and Facebook (FB - Get Report) .

Facebook CEO Mark Zuckerberg said in a Sept. 5 statement, "The decision to end DACA is not just wrong. It is particularly cruel to offer young people the American Dream, encourage them to come out of the shadows and trust our government, and then punish them for it."

Using President Trump's favorite communication device, Apple (APPL CEO Tim Cook tweeted, "250 of my Apple coworkers are #Dreamers. I stand with them. They deserve our respect as equals and a solution rooted in American values."