So again, when we form the dimer, when this conformational change takes place, the carboxyilic, the Sea terminal end of one tyrosine kinase domain moves into the aesthetic side of the posing tyrosine kinase domain. And this is what we call the cross phosphorylation process. So in the same way that in the insulin pathway we carry out crossfosphorylation here, we also carry out crossfosphorylation, except in this particular case it's not the activation side, but it's the C terminal tail that moves into the active side of that opposing tyrosine kinase domain. So basically in this step we conclude the following the binding of the EGF molecules onto these binding sides basically causes this dimerization process to actually take place. And what that leads to is the cross phosphorylation of these C terminal tails on both of these sides. And what this cross phosphorylation process actually does is it creates attachment points for further attachment of other proteins as we'll see in just a moment.