An important part of the nucleus is formed by nuclear lamina. Nuclear lamins form a network of filaments at the nucleoplasmic site of the nuclear membrane. Two main subtypes of nuclear lamins can be distinguished, i.e. A type lamins and B type lamins. The A type lamins comprise a set of three proteins arising from the same gene by alternative splicing, i.e. lamin A, lamin C and lamin Adel10, while the B-type lamins include two proteins arising from two distinct genes, i.e. lamin B1 and lamin B2. The nuclear lamins comprise a unique subclass of the intermediate filament protein family. They share a molecular domain organisation with the other intermediate filament proteins in that they are fibrous molecules that have an aminoterminal globular head, a central rod of alpha helices and a carboxy terminal globular domain. Many biochemical and molecular features of lamins have been studied, but their functions remain still largely undetermined. One of the functions ascribed to the lamina is the maintenance of the structural integrity of the nucleus.