FIGURE 7 

Time ordered sequential events control cellular decision of migration. Schematic representation of events regulating the initiation, maintenance, modulation and stopping of cell migration. (A) The migratory response depends on a certain threshold of gene activity, as indicated by the dashed line, and proceeds as long as no context information is provided via a stop signal or the sustained activation is depleted. (B) Summary scheme of the model for migration. A first pulse-like HGF stimulus is required to transform the cell into a sensitive state for migration. To initiate and sustain migration, a second input preferably through the EGF-R signaling pathway is required. This second input can be modulated by a number of genes. Context information is integrated through the PKA pathway, which can stop migration at any point in time.