Second, the definition of the drug pocket and covid19 pocket has to be the same to eliminate the flows associated with any pocket defining algorithm, for example, the drug pocket could be extracted by making a 4.5 angstrom cut of the amino acids around the drug, but this method was avoided because it might lead to taking too many amino acids making the pocket bigger than it has to be. In addition to that, using the Fpocket algorithm to define the pocket in both cases eliminates some of the flaws of the Fpocket algorithm, and no algorithm is without flaws.