A polycyclic aromatic compound, Benzo[ a ]pyrene (Benzo[ a ]pyrene), was the first chemical carcinogen to be discovered .

Nonetheless, the team developed the technique to map the parts of the DNA damaged by the major chemical carcinogen, benzo[α]pyrene found in cigarettes.

They then used that technique to map all damage caused by the major chemical carcinogen — benzo[α]pyrene.

They then used that technique to map all damage caused by the major chemical carcinogen – benzo[α]pyrene.

They then used that technique to map all damage caused by the major chemical carcinogen -- benzo[α]pyrene.