Cell communication is the ability of cells to communicate with adjacent cells within an organism.Cells transmit and receive signals acquired from fellow cells or by the environment surrounding the cell. The signals are transmitted across the cell membrane to prompt a response. The signal can cross the membrane itself, or it can interact with receptor proteins that contact both the interior and exterior of a cell. The correct receptor needs to be present on the cells surface to be able to respond to the signal. Signals pass from protein to protein when the signal travels through the cell membrane entering the cell. The signal continues its journey to its destination, be it the nucleus or any of the other structures or organelles in the cell.