Nuclear matrix

In biology, the nuclear matrix is the network of fibres found throughout the inside of a cell nucleus and is analogous to the cell cytoskeleton. The exact function of this matrix is still disputed, and it's very existence has recently been called into question. There is evidence that the nuclear matrix is involved in regulation of gene expression in Arabidopsis thaliana.

Problems with nuclear matrix hypothesis
While a matrix structure may be viewed once the nucleus has been isolated, it has been suggested that the process of isolation itself induces fibre-like artifacts. Furthermore, it has been noted that experimental observations of the movement of RNA within the nucleus corresponds well to that expected from a purely diffusive process.

Finally, one may argue that a nuclear matrix is not necessary for nuclear function, and thus Occam's Razor sides with the simpler explanation