Motivation: Development of an in silico cell, a computer resource for modeling and analysis of physiological processes, is an urgent task of systems biology and computational biology. Mathematical modeling of the genetic regulation of one of the basic metabolic processes, the pentose phosphate pathway, is an important problem to be solved as part of this line of work. Results: By using the GeneNet technology, we reproduced the gene network of the regulation of the pentose phosphate pathway in the E. coli cell. Mathematical models were constructed by the method of generalized Hill functions to describe the efficiency of enzyme systems. Availability: Models are available on request. Gene network is available at http://wwwmgs.bionet.nsc.ru/mgs/gnw/genenet/viewer/index.shtml.