And proteins come from DNA. So remember, inside the DNA we have genes and the genes actually code for the proteins. So what differentiates pathway one from pathway two is the type of genes that are expressed and the type of proteins that are formed. So this is known as differential gene expression. So it's differential gene expression that allows cell one to follow pathway to and form a neuron while cell two follows pathway two to form a skeleton muscle cell. So it's differential gene expression that allows cell differentiation to actually take place.