ABSTRACT
Cells communicate with each other through cell signaling. Signals such as proteins, amino acids or steroids are either bound to the cell membrane of a signaling cell (A) or released from the cytoplasm of the signaling cell (B).
The target cell(C) then either receives the membrane-bound signal which is still attached to the signaling cell or it receives the secreted signaling molecules.
The signals attach to the target cell at specific surface proteins called receptors.
Each target cell is programmed to respond in a specific way to a given set of signals. When deprived of appropriate signals, the cell will undergo programmed cell death, also known as apoptosis.
