All prokaryotes have cell walls but only some have euk have cell wall i. e. plants and fungi. Info is stored in dna in forms of genes. In any one cell type ~10000 are expressed at various levels. Some are expressed very high and some are expressed very low. The expression of correct genes is essential for growth and differentiation of all cells. Those 10000 genes which 10000 are expressed depends on what cell type is. Those expressed in muscle are a lot diff than liver. Human genome encodes ~25 000 different protein encoding genes. Most disease states result from alterations in expression of one or more genes. Many are result are from gene being udner expressed or over expressed. Overexpression or underexpression can lead to diseased state. Correct expressino is crucial in matining healthy org. By manipulating gene expression, we have potential to prevent or reverse disease. If we can corect gene expression, we shudlbe able to cure disease.