Hopf bifurcation analysis for a mathematical model of P53-MDM2   interaction
  In this paper we analyze a simple mathematical model which describes the interaction between the proteins p53 and Mdm2. For the stationary state we discuss the local stability and the existence of the Hopf bifurcation. Choosing the delay as a bifurcation parameter we study the direction and stability of the bifurcating periodic solutions. Some numerical examples and the conclusions are finally made. 
Mihaela Neamtu, Raul Florin Horhat, Dumitru Opris