Figure 2. The distribution of gene activities in heterogeneous cell populations with a population size of 50,000.

These distribution are for majority rule signaling with positive and continuous gene activities. a) The activity of the output node is close to a normal distribution due to many pathways arriving at the output node; b) Signal statistics at the gene NFkB, which is an internal node lying at the end of a chain of links (see Fig. 1), is close to log-normal. (see discussion in the text).