Now, in the EGF signaling pathway we discussed four different types of protein kinases. So just like in the case of insulin here, the EGF receptor also contains a tyrosine protein kinase that is needed to actually initiate that signaling pathway. And then we also examined three other examples of kinases. So we spoke about rats which were actually needed to activate mex, and then the mechs are needed to activate hercs. And these irks are protein kinases that move into the cell, into the nucleus of our cell, and inside the nucleus, they essentially activate these transcription factors which increase the rate of expression of genes and that ultimately allows the cell to produce many proteins that ultimately allow the cell to grow and divide, which is what the physiological effect is in this particular case. So when we spoke about this pathway we said that the physiological effect might be, for instance, actually sealing off that cut that we might experience on the epidermal cells of our skin.