It is interesting to note that Hp isolated from gastric cancer patients is often non-cultivable, despite the fact that the bacteria are detectable by other methods (i.e., PCR or histology), and that coccoid forms have been indeed more frequently found in gastric mucosa of gastric cancer patients than in that of peptic ulcer patients (Chan et al., 1994). The gene discussed is HP; the disease is peptic ulcer disease.