ACE2 and COVID-19: Interestingly, the P136–155 (RLFRKSNLKPFERDISTEI) peptide, highly recognized by our serum samples and hybridoma supernatants (Figures 2, 3), is located in RBM according to structural analysis of the RBD-ACE2 complex and was shown to elicits neutralizing antibodies in COVID-19 patients (36).