The affinity of Beta RBD for ACE2 was itself 19-fold higher than we previously measured for ancestral Wuhan RBD (Figure 4G) and the increased affinity compared with XBB.1.5 may give BA.2.86 a transmission advantage against XBB.1.5-derived strains of SARS-CoV-2, which until recently dominated infections globally,26 although animal studies would be required to formally demonstrate this. The gene discussed is ACE2; the disease is infection.