Fig. 2

The network of cell apoptosis regulation induced by DNA damage [34]. The signals will be transmitted from the upstream signaling proteins to the transcription factors (e.g.,p53 and E2F1), then the transcription factors will regulate the transcription of apoptosis regulators (e.g., Bax, Bcl-2, Apaf-1 and Caspases). Rectangle, diamond and ellipse nodes represent signaling proteins, transcription factors and regulated genes, respectively. Each activation interaction is denoted as a green edge with an arrow head and each inhibition interaction is represented by a red edge with a flat-head. The solid and dash lines represent signal transduction and transcription regulation, respectively