[3][4] Although the centrosome has a key role in efficient mitosis in animal cells, it is not essential in certain fly and flatworm species.

[5][6][7] Centrosomes are composed of two centrioles arranged at right angles to each other, and surrounded by a dense, highly structured[8] mass of protein termed the pericentriolar material (PCM).

In general, each centriole of the centrosome is based on a nine-triplet microtubule assembled in a cartwheel structure, and contains centrin, cenexin and tektin.

[11] The centrosome was discovered jointly by Walther Flemming in 1875 [12][13] and Edouard Van Beneden in 1876,[14][13] and later described and named in 1888 by Theodor Boveri.

During mitosis, the nuclear membrane breaks down, and the centrosome-nucleated microtubules can interact with the chromosomes to build the mitotic spindle.

Moreover, development of the fruit fly Drosophila is largely normal when centrioles are absent due to a mutation in a gene required for their duplication.

The function of centrosomes in this context is hypothesized to ensure the fidelity of cell division, because it greatly increases the efficacy.

[20] Centrosome alterations in cancer can be divided in two subgroups — i.e., structural or numeric aberrations — yet both can be found simultaneously in a tumor.

These modifications may produce variations in centrosome size (usually too large, due to an excess of pericentriolar material).

In addition, because centrosomal proteins have a tendency to form aggregates, centrosome-related bodies (CRBs) are often observed in ectopic places.

[21][23] These structures may look very similar, yet detailed studies reveal that they may present very different properties, depending on their proteic composition.

The presence of an inadequate number of centrosomes is very often linked to the appearance of genome instability and the loss of tissue differentiation.

It has been observed that loss of the tumor-suppressor p53 produces superfluous centrosomes,[25] as well as deregulating other proteins implicated in cancer formation in humans, such as BRCA1 and BRCA2.

It is evident that some parts of the centrosome are highly diverged in the model species Drosophila melanogaster and Caenorhabditis elegans.