LOS ANGELES — Zhao Zhenzhong, author of the best-selling novel “Colors of the Mountain,” has died. He was 57.

Zhao’s friend and translator, Yaxue Wu, confirmed the death on Monday. Zhao had been battling lung cancer for several years.

Zhao’s young adult novel “Colors of the Mountain” sold more than a million copies in China and won many prizes. But it was considered controversial, not least because it dealt with the powerful religious beliefs of indigenous tribes.

“Colors of the Mountain” tells the story of a group of hardy peasants in the Northern Hemisphere who cross paths with migrants from the plains of Central Asia. Under their harsh winters and fields of wild weeds, they fight for survival and to keep their innocence against the demands of their families and townspeople.

The novel touches on themes of mysticism, war and religion, in the way that many books do for young readers — and like many Chinese books, it plays coy with the concept of good and evil.

“I was interested in having a quiet encounter with Chinese tradition but making it new,” Zhao said in an interview with The Associated Press in March 2015.

“I am a newcomer in Chinese folklore and literature,” he added. “So I see certain phenomena of their traditions. I discover things. At first, I think, ‘Whoa, that sounds really strange,’ but after I became familiar with them, I recognized things.”

Zhao was born on July 17, 1963, in Shanghai, and spent a year in England after his family moved to the city. He soon began to write stories while he was an adolescent.

Zhao graduated from the Shanghai University of Political Science and Law in 1994. His next novel, “4 Seasons,” was translated into English in 2016.

He is survived by his wife, three sons and a daughter. Funeral arrangements are pending.