A hypothesis of the power-frequency relation of oscillations in cancer cells. A schematic picture of the frequency f and of the power P of the electromagnetic field generated by microtubules in normal and cancer cells. Cancer cells with the Warburg and the reverse Warburg effects generate electromagnetic fields with lower and higher power than cells in a healthy tissue, respectively, causing frequency shifts in opposite directions. The generated power is determined by energy supply and damping. fT, fW, and fRW are frequencies of microtubule oscillations of normal cell and cancer cells with the Warburg and the reverse Warburg effect, respectively.