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. Definition. noun, plural: cell walls. A membrane of the cell that forms external to the cell membrane whose main role is to give cells rigidity, strength and protection against mechanical stress. It is found in cells of plants, bacteria, archaea, fungi, and algae.Animals and most protists do not have cell walls.Supplement. membrane of the cell that forms external to the cell membrane whose main role is to give cells rigidity, strength and protection against mechanical stress. It is found in cells of plants, bacteria, archaea, fungi, and algae. Animals and most protists do not have cell walls. Supplement.