It has been found in a research that breast cancer cells control many genes together simultaneously due to the presence of the hormone estrogen in women, which destroys 14 genes at once. The breast cancer cells loop the DNA of the genes and enhance the cancer.

The research used normal human breast epithelial cells along with two animal models. The normal-cell model was used to check if the cells, when exposed to nine chemicals similar to estrogen for a long duration, would start silencing genes.

It was found that continuous exposure to estrogen-similar compounds can permanently silent genes present in this region.

In normal breast epithelial cells, a transcription site takes place as 14 gene controlling sites come together.

However, this kind of coordinated pairing cannot be seen in breast cancer cells, and the DNA loops get tangled up into a complex and form a dead knot, which leads to progress of cancer development.

As the DNA loses its flexibility, certain genes are made silent, and this inflexible DNA serves as a good marker for understanding the behavior of cancer cells while in exposure to compounds similar to estrogen.