“…In view of the unequivocal importance of exogenous factors in lung carcinogenesis, the genetic predisposition can be explained by inherited factors modulating individual susceptibility to carcinogens (Strong, 1977;Nebert, 1978;Mulvihill, 1978;Miller, 1980). Attempts were made to relate isozymes and DNA polymorphisms to a genetic predisposition (Seidegard et al, 1986;Heighway et al, 1986;Gerber and Scoggin, 1986;Iannuzzi and Miller, 1986). Since most environmental carcinogens undergo metabolic activation or inactivation by genetically controlled enzyme systems, the determination of the activity and inducibility of the enzymes involved is a logical experimental approach for an individual risk assessment.…”