NDUFB6 and infection: Unexpectedly, however, nearly half a century ago, Lieb and co-workers found that when E. coli is infected with λN-cI- double mutant at a high m.o.i. (multiplicity of infection) of 50 or more phages per cell, almost all the cells survive and apparently stable lysogens appear at a frequency of about 10% [11,12].