When I interviewed Theranos's Elizabeth Holmes recently, she said she was the only female startup founder to singlehandedly found a technology or health care company and then take it to billions in valuation. There have been others, she said, but they all had co-founders. (Holmes was quick to explain that she didn't mean to take anything from their accomplishments by noting that they had co-founders--it's just that in one particular way, their achievements are different from hers).

I still think that, within the venture-backed world of Silicon Valley, Holmes is probably right. I've been looking pretty hard, and I haven't found another woman who's done exactly what she has: raised outside money by herself, and then founded a tech or health care company that went on to be valued at multiple billions. While it may seem like raising outside money would actually make it easier to build such a company, even that achievement is often out of reach for women: Less than 3 percent of venture capital goes to female CEOs. So for women without a male co-founder, bootstrapping may well be the "easier" option.

Either way, Holmes's comment, and the conversations I've had with female venture capitalists and entrepreneurs since then, reminded me that there are a slew of terribly accomplished female entrepreneurs out there, but we don't hear much about them. That's a shame, because women entrepreneurs, like everyone else, need role models. If Holmes can do it, perhaps they can do it. Here are some women entrepreneurs in both health care and tech who might not precisely fit Holmes's category (no co-founder, venture backing), but definitely deserve to be better-known.

Judith Faulkner

Founder and CEO, EPIC Systems

Faulkner is the founder and CEO of EPIC Systems, the leader in the incredibly hot, and almost as controversial, field of electronic medical records. EPIC had a 2014 revenue of $1.8 billion and counts among its clients Kaiser Permanente, CVS MinuteClinic, and the Mayo Clinic. Epic's success is all the more impressive considering that Faulkner bootstrapped the company on her own, starting with just $6,000. EPIC has been completely self-funded since then, and is privately and employee-owned. To make sure it stays that way, Faulkner has created a charitable foundation for her own stock in the company. 

Diane Greene

Co-founder and CEO, VMWare

In 1998, Greene was a member of the five-person team that co-founded VMWare, and became its president and CEO. VMware provides cloud and virtualization services, which allow servers to run multiple applications and operating systems at once, to large enterprises. VMWare was acquired by EMC Corp. in 2004, but in 2007, EMC spun out 10 percent of VMware in a billion-dollar IPO--the biggest since Google had gone public in 2004. In 2008, EMC fired Greene as CEO of VMware, causing the company's stock to drop 24 percent in one day. Greene now sits on the board of directors of both Google and Intuit, and is said to be working on stealth startup Demeterr

Sandy Lerner

Co-founder, Cisco

Yes, it seems ridiculous to put Lerner on a list of "not-so-well-known" entrepreneurs--she co-founded Cisco Systems, the company that dominated the sale and discussion of routers, switches, and networking gear literally for decades. Yet I know she's not a household name, because I've repeatedly heard Lerner referred to as "he," even among people who really should know better. But Lerner and her then-boyfriend, Len Bosack, co-founded Cisco in 1984. In 1990, the man they brought in to be CEO of the company fired Lerner, and Bosack quit in support of her. Lerner went on to found cosmetics company Urban Decay, which she sold to LVMH in 2000. Lerner is now working--and farming--to promote sustainable, organic, and humane agriculture practices.

Nina Vaca

Co-founder and CEO, Pinnacle Technical Resources

Nina Vaca came to the U.S. from Ecuador with her family while she was still a child. Both her parents were entrepreneurs, but Vaca's own path in entrepreneurship had a tragic start: In 1989, her father was shot and killed during a robbery at one of his businesses, and Nina and her sister took over the business, then sold it. In 1996, after graduating from college and working at another computer company, Vaca co-founded Pinnacle Technical Resources, an IT staffing and payroll company. In 2011, Vaca bought out her business partner's share and became the sole owner of the company. In 2014, Pinnacle had revenues of $665 million, up from $165 million in 2010. That landed it at No. 1,840 on the Inc. 5000 in 2015, and made it the No. 1 company on the Women Presidents' Organization's list of fastest-growing companies in 2014. 

Anne Wojcicki

Co-founder, 23andMe

For a while, Wojcicki was probably best-known as the wife of Sergey Brin, the co-founder of Google. But Wojcicki had her own startup plans: In 2006, she co-founded 23andMe, encouraging people to spit into a tube that they could then mail to the company. For $99, they'd get information about their genetic history and possible disease proclivity. People who showed a likelihood to develop a particular disease could join disease-specific groups and agree to work with researchers trying to find a way to cure or prevent it. In 2013, after 23andMe had acquired about half a million customers, the U.S. Food and Drug Administration shut down the genetic-testing part of 23andMe (customers could still get information about their ancestry). That forced 23andMe to go global, and the company recently announced it was wading into drug development. 23andMe has raised about $111 million so far, and is valued at over $1 billion.