The authors mention a single gene, lpp0194, encoding an integrase/excisionase. However, in previous publications, two genes are listed (lpp0193 for the excisionase and lpp1094 for the integrase). Unless I am mistaken, the authors did not mention this lpp0193 gene. How do the authors explain that inactivation of the integrase (lpp0194 gene) leads to a deficiency in the excision of pP36 from the chromosome, even though the excisionase gene (lpp0193) of the ICE has not been modified? Is there really only a single mutation in the entire ICE? Was the entire ICE region sequenced in the mutant to verify the absence of secondary mutations?