Differential expression of the operon in a biofilm.

Type VII protein secretion systems play an important role in the survival and virulence of pathogens and in the competition among some microbes. Potential polymorphic toxin substrates of the type VII secretion system (T7SS) in are important for competition in the context of biofilm communities. Within a biofilm, there is significant physiological heterogeneity as cells within the population take on differential cell fates.