According to Bill Gates, there are millions of people like who are making a difference in our world. And, while they may be too humble call themselves heroes, he can think of no better word to describe them.

He wants to call attention to some of those heroes. They are just a few of the many people using their talents to fight poverty, hunger, and disease and provide opportunities for the next generation. To all of them, wherever they are, he says thank you. The world is a better place because of what they do.

Here are the stories of five of these heroes. Their lives inspire me. I hope they’ll inspire you too.

1. Segenet Kelemu

After working abroad for 25 years as a plant pathologist, she returned to Africa in 2007 to lead a new generation of scientists dedicated to helping the world’s smallholder farmers grow more food and lift themselves out of poverty

2. Mathew Varghese

Dr. Mathew Varghese, an orthopedic surgeon at St. Stephens Hospital in Delhi, runs India’s only polio ward, where he provides reconstructive surgery for polio patients to give them greater mobility.

3. Ada Okoli

In 2014, Ada Okoli, a Nigerian doctor, made international headlines when she became infected with Ebola while caring for her patients in a Lagos hospital. She has now dedicated her medical career to the research, treatment, and prevention of future epidemics. Her courage and her optimism are inspiring.

4. Anna Rosling

Anna Rosling, the co-founder of Gapminder, is dedicated to using art and science to help us make sense of a complicated world. She uses photos and big data to create an engaging portrait of how people live around the world. Thanks to her efforts we can see ourselves and our world more clearly.

5. Camille Jones

Using hands-on learning approaches, she leads a schoolwide effort to inspire students to explore the possibilities that science, technology, engineering, arts, and math can offer. Thanks to her work, she’s helping more students in our state dream big.

Read more on GatesNotes.