NEK2 is a serine/threonine kinase involved in mitotic regulation. NEK2 also known as serine/threonine protein kinase Nek2, NimA-related protein kinase 2, and HSPK21, can be expressed as 3 different isoforms as a result of alternative splicing.. The predicted molecular weight of full-length protein is approximately 52 kD. Isoform 1 and isoform 2 forms homo- and heterodimers; isoform 1 has a nucleolar targeting/retention signal in C-terminal domain. Isoform 2 is missing the C-terminal sequence and remains mainly in the cytoplasm. Isoform 1 plays a role in centrosome splitting and phosphorylates and activates NEK11 is G1/S arrested cells. NEK2 accumulates throughout S phase, becoming maximal in late G2 with expression similar to that of A and B cyclins. Isoform 1 is not present in cells arrested in G2/M prometaphase. Both isoform 1 and 2 are expressed in peripheral T cells and many other transformed cell types. The NEK2 protein has been shown to interact with the TERF1 protein. The 8A6 monoclonal antibody recognizes human NEK2 and is useful for Western blotting.