An important consequence of the CR mechanism is the fact that the charging state of a protein is an annealed variable and can therefore exhibit thermal fluctuations, a theoretical prediction borne out by experiments . These thermal protonisation/deprotonisation fluctuations engender fluctuations of both the protein charge as well as the protein dipole moment that in turn lead to capacitance and polarizability of the protein. The charge and the dipole moment are then together at the origin of the fluctuation interactions usually referred to as the Kirkwood-Shumaker (KS) forces . They have been quantified in detailed simulations of protein-protein interactions by Lund and Jönsson and Barroso da Silva and Dias . Upgrading the original KS approach, the fluctuation interactions were cast into a more appropriate theoretical framework of monopole and dipole Casimir-type thermal fluctuation interactions or within the zero frequency Lifshitz term in the general theory of van der Waals interactions .