Yellapragada Subba Rao (12 January 1895 – 8 August 1948) was a pioneering Indian biochemist who discovered the function of adenosine triphosphate (ATP) as an energy source in the cell,developed methotrexate for the treatment of cancer and led the department at Lederle laboratories in which Benjamin Minge Duggar discovered chlortetracycline (Aureomycin) in 1945. Highly inspiring life of a great human being who dedicated his life for a better world..!!