Molecular cell biology is a marriage of two distinct, yet complementary, disciplines. In its traditional sense, the term 'molecular biology' refers to study of the macromolecules essential to life — nucleic acids and proteins. The field of cell biology is a natural extension of this, integrating what we know at the molecular level into an understanding of processes and interactions at the cellular level. Only by combining both fields can we paint a broad picture of essential biological processes such as how cells divide, grow, communicate and die.