Former YouTube CEO Susan Wojcicki, a tech pioneer who was one of Google’s earliest employees, has died after living with lung cancer for two years, according to her husband.

“It is with profound sadness that I share the news of Susan Wojcicki passing. My beloved wife of 26 years and mother to our five children left us today after 2 years of living with non-small cell lung cancer,” Dennis Troper wrote in a Facebook post.

Troper said Wojcicki was “not just my best friend and partner in life, but a brilliant mind, a loving mother, and a dear friend to many.”

“Her impact on our family and the world was immeasurable. We are heartbroken, but grateful for the time we had with her,” Troper said. “Please keep our family in your thoughts as we navigate this difficult time.”

Wojcicki – who was one of the most prominent women in Silicon Valley – had been involved with YouTube’s parent company Google from its earliest days, when its two founders worked out of her garage in California to build a search engine. She later became Google’s 16th employee and had worked at the company for nearly 25 years.

Google CEO Sundar Pichai expressed condolences in a post on X early Saturday, saying Wojcicki was “core” to Google’s history.

“She was an incredible person, leader and friend who had a tremendous impact on the world and I’m one of countless Googlers who is better for knowing her. We will miss her dearly,” Google CEO Sundar Pichai said on X.

Wojcicki had served as YouTube’s CEO for nine years before announcing last year in a blog post that she would be “stepping back” from her leadership role to focus on her family, health and personal projects that she was passionate about, CNN previously reported.

She oversaw YouTube during the web’s pivotal transition toward social media, but also as online platforms came under increasing scrutiny for spreading misinformation, hate speech and other harmful content.

“I’m so proud of everything we’ve achieved,” Wojcicki wrote when announcing she was stepping down in 2023. “It’s been exhilarating, meaningful, and all-consuming.”

This is a developing story and will be updated.