Mycoplasma and other Gammaproteobacteria found in pancreatic cancers was recently shown to metabolize gemcitabine, a pyrimidine nucleoside, using a long isoform of cytidine deaminase (17), and it is possible that this enzyme has additional unrecognized effects on DNA repair or pyrimidine metabolism. The gene discussed is CDA; the disease is familial pancreatic carcinoma.