CYP1B1 and neoplasm: They concluded that CYP1B1 is commonly expressed in human lung and it may be an important phase I enzyme with respect to human lung carcinogen metabolism.49 Marta and research group claimed to be the first who studied the frequency of CYP1B1 polymorphisms in pancreatic cancer as well as the relationship between CYP1B1 variants and mutations in ras genes (K-, H- or N-ras) in human neoplasm.