Figure 2

Cell proliferation and death (genetic regulation) for colorectal cancer. This figure shows the genetic model with regulation signals as inputs. p53 is activated when DNA is damaged and leads the cell to apoptosis. SMAD is activated through TGFβ receptors during hypoxia and inhibits cell proliferation. Overpopulation inhibits cell proliferation through activation of APC. RAS promotes cell proliferation through growth factor receptors when sufficient oxygen is available for the cell, that is, there is no hypoxia. This flow chart was developed from knowledge available from bibliographic resources [15,16] and from the Knowledge Encyclopedia of Genes and Genomes [53,54].