TTFields are wave-like alternating electric fields. The forces generated by TTFields interfere with the cell division process in cancer cells. First of all, finger-like fibers called microtubules rely on their electrical charges to form.
In the presence of TTFields, microtubules are not necessarily able to develop normally and are therefore unable to pull the DNA apart during cell division. This can result in cell division slowing down or stopping, which in turn leads to cell death. If the cell continues to divide in the presence of these fields, the hourglass shape that appears during this process may push the cell components to the center of the dividing cell. This may result in structural damage and cell death. TTFields act on dividing cancer cells but do not usually affect healthy resting cells.