SH2D3C and Middle East respiratory syndrome: The nsp3 segment, delineated as highly variable in the above comparison between the human SARS-CoV-2 and its closest animal homologs, is also the most divergent upon alignment of the human SARS-CoV-2 with the previous SARS-CoV-1 (responsible of the 2002 epidemics) [12], and even more dissimilar in the MERS-CoV (agent of the Middle East respiratory syndrome) [13] (Figure 2).