Subway cofounder and longtime CEO Fred DeLuca has died at age 67 on Monday, the company said Tuesday.

DeLuca had been diagnosed with leukemia two years ago but remained fairly active with the company. Earlier this year, he relinquished day-to-day control of Subway to his sister, Suzanne Greco, so he could focus on his health. 

DeLuca cofounded Subway in 1965, when he was 17 years old, eventually growing the business to become the industry's largest chain, with more than 44,000 locations worldwide.

He was also an active member of the International Franchise Association.

DeLuca leaves behind his wife, son and sister.