The story of a retired Tsinghua University professor who anonymously donated his life savings to poor students, despite being diagnosed with terminal lung cancer, has moved many people.

Zhao Jiahe, a retired finance professor of Tsinghua University, had devoted his life to education and funding impoverished students. He donated his life savings of 15 million yuan ($2.2 million) to support over 2,000 high school students in need across the country.

He began teaching at Tsinghua University in 1955, after graduating from the school's department of radio electronics. "I love teaching. The happiest thing for me is for others to understand what I have taught," Zhao once said.

In 1985, he helped establish the school of Economics and Management at Tsinghua University.

Apart from his dedication to work, Zhao was mostly known for being thrifty. He had worn a synthetic-fiber sweater, worth only $1, for more than 10 years, and the most expensive piece of furniture in his home was an outdated TV.

Even when he served as a guest professor at the University of Texas in 2001, Zhao still lived a simple life and never wasted anything. After three years of teaching abroad, Zhao declined favorable offers from the university and went back to China.

The first thing he did after his return was to hand over the $200,000 he had saved to his students specialized in financial investment. When his savings had reached 5 million yuan in 2006, the 72-year-old Zhao started aiding poor high school students from all over the country. He would donate the money anonymously under the name of "a retired Tsinghua professor", an effort known only to a few people around him.

In 2011, Zhao became diagnosed with advanced lung cancer, but he continued to donate his money to support the poor students, and choose to buy himself the least expensive medicines for treatment.

He also established a foundation in 2012, aiming for long-term support for the students, especially those from impoverished families in western China.

In 2012, Zhao succumbed to lung cancer and donated his body for scientific research. In his last moments, Zhao said," I have done what is most worth doing. I have no regrets now."

Zhao's "secret" was kept until 2016, when his story was made public.