Chi H. Mak 52 studied base stacking driving forces in DNA. He carried out large-scale molecular simulations to reveal the thermodynamic parameters (driving forces) behind the stacking interaction in DNA. To calculate the stacking free energy or Gibbs free energy, the author used the Monte Carlo calculation method and simulated purine and pyrimidine bases surrounded by many solvent molecules within a cubic box of up to 134 cubic angstroms in size. The author studied thermodynamic driving forces and physicochemical origins behind DNA-solvents stacking interaction. The computer simulation leads the author to conclude that the solvent's entropy of hydrophilic origin is the major driving force for base stacking.