Docetaxel

Docetaxel is a taxan, an anticancer agent obtained from the bark of the yew tree. It belongs to a class of chemotherapy drugs called plant alkaloids.

The plant's toxic properties have been known since prehistory, when it was identified as the "Tree of Death".
In fact, Yew is an example of a plant with medicinal value that can be poisonous if eaten. Just because something is ‘natural’, it isn't necessarily safe to casually eat or use. In the fall, the bright red berries of the yew are especially attractive. Poisonous parts of the plant include the needles and the seed found inside the berries.

In the history, it happened that children have been poisoned by eating berries and adults by brewing tea from the needles. But it was only in the 1960s that taxanes were rediscovered in the US as potential treatment.
Today they are widely used as compounds in fighting cancer.

In patients with cancer, cell division is no longer controlled as it is in normal tissue. Antimicrotubule agents, such as Docetaxel, inhibit the microtubule structures that are part of the cell's apparatus for dividing and replicating itself. Inhibition of these structures ultimately results in cell death.