Use Retin-A exactly as your doctor has prescribed it for you. Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended. Do not take by mouth. Retin-A is for use only on the skin.
Definition of wall for English Language Learners : a structure of brick, stone, etc., that surrounds an area or separates one area from another : the structure that forms the side of a room or building
Cell wall is a tough, rigid layer that surrounds some types of cells. Cell wall is a characteristic feature to cells of plants, bacteria, fungi, algae and some archaea. It is located outside the cell membrane. The major function of the cell wall is to provide rigidity, tensile strength, structural support, protection against mechanical stress and infection. It also aids in diffusion of gases in and out of the cell.