CDA and familial pancreatic carcinoma: These researchers examined tumor specimens from 113 pancreatic cancer patients and found bacteria in 76% of tumor specimens, primarily Gammaproteobacteria, which can express the long form of CDD (cytidine deaminase) and can metabolize the active form of gemcitabine (2′,2′-difluorodeoxycytidine) into the inactive form, 2′,2′-difluorodeoxyuridine.