Melinda French Gates endorsed President Biden on Thursday, her first-ever presidential endorsement, she wrote on the social media platform X.

Why it matters: French Gates is one of the most wealthy women philanthropists in the world. While she hasn't immediately committed any money to Biden's campaign, the endorsement is a signal boost for the president as other mega-donors have backed former President Trump.

French Gates said earlier this year that she was resigning from the Bill & Melinda Gates Foundation, which she co-founded with her ex-husband Bill Gates. She said she would continue to focus on gender equity.

Biden's emphasis on protecting reproductive rights is a big reason for her endorsement, French Gates said, writing in a CNN op-ed out Thursday that former President Trump's "first term in office endangered the health of women."

Driving the news: "This year's election stands to be so enormously consequential for women and families that, this time, I can't stay quiet," Gates wrote on the social media platform X.

"Women deserve a leader who cares about the issues they face and is committed to protecting their safety, their health, their economic power, their reproductive rights, and their ability to freely and fully participate in a functioning democracy," she said.