nuclear lamins are intermediate filament proteins that constitute the lattice-like matrix at the inner face of the nuclear membrane that underlies the nuclear envelop. The lamins, highly conserved throughout evolution, are encoded by three genes in the human: LMNA, LMNB1, and LMNB2. The A-type lamins (lamin A/C) are developmentally regulated and are generally expressed in differentiated cells. The anchoring of chromatin to the nuclear lamina is involved in the control of gene expression and in DNA replication and repair. During mitosis, the nuclear lamina is reversibly disassembled as the lamin proteins are phosphorylated. B-type lamins are phosphorylated within minutes of engaging the IgM surface receptor of resting splenic B cells. Nuclear lamins are cleaved by caspases during apoptosis. Note: This description may include information from UniProtKB.