The current hypothesis is that such receptor binding domain is also employed by 2019-nCoV. That being said, non-conserved mutations (that is, deviations from the known SARS-CoV amino-acid sequence in these regions) were recognized in structural regions that interact directly with ACE2. Thus, it was suggested that some particular amino acid substitutions are to be held responsible for overall cell-affinity differences between the two viruses. Needless to say, identifying particular amino acids that significantly contribute to ACE2-binding in 2019-nCoV is expected to lead to the development of effective vaccines. Based mostly on "chemical intuition", Morse et. al. have predicted that several amino-acid substitutions would result in a greater affinity for 2019-nCoV, due to stronger noncovalent interactions with specific, corresponding residues in ACE2. In this context, the following substitutions were addressed (SARS-CoV/2019-nCoV): V404/K417, Y484/Q498, L472/F486, and C474/Q492. However, reliable assessments of the relevant noncovalent interactions -that may rise from subtle electronic effects which must be explicitly considered -are to be obtained in order to confirm/refute predictions of this sort.