 This raises many questions on what is necessary versus what is sufficient for constituting a centromere.As neocentromeres are still a relatively new phenomenon in cell biology and genetics, it may be useful to keep in mind that neocentromeres may be somewhat related to point centromeres, holocentromeres, and regional centromeres.Whereas point centromeres are defined by sequence, regional and holocentromeres are epigenetically defined by where a specific type of nucleosome (the one containing the centromeric histone H3) is located.