ACE2 and infection: Based on pairwise sequence alignments to hACE2 (Fig. S2), we modeled the RBD interaction with ACE2 molecules from species reported to support entry and infection in vitro (ferret, macaque, mink, cat, pig, guinea pig, and dog) as well as those from species reported to support little to no infection (mouse, chicken) (Fig. S1) (25, 27).