Cyber Nucleic Acid, shortened to CNA, is the fundamental building block of all Cybertronian life. Much like a human's DNA, CNA is the genetic blueprint of a Cybertronian's biological system.
Shockwave used the CNA of a fossilized Predacon to clone Predaking, a "beast machine" who later betrayed the Decepticons after Megatron, Starscream, Knock Out and Shockwave destroyed Project Predacon. The CNA was later used to rebuild Cybertron after it was mixed with a stabilized form of Synthetic Energon. The mixture, known as Cybermatter, revived Cybertron and allowed Cybertronians to return to their damaged home world.