Mechanistically, the two consecutive serines (aa179 and aa180) in the polybasic binding region (PBR) of Rap1b are prone to phosphorylation, while the following cysteine (aa181) keeps the most limited prenylation and activation under the septal inhibition from phosphorylation to achieve the recurrent cycle of the membrane and cytoplasmic transfer for the most favorable balance in terms of function and energy saving during different physiological processes, including viral infection [22]. Here, RAP1B is linked to viral infectious disease.