S2P6, an antibody isolated from a COVID-19 convalescent patient, can bind to S proteins of SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV-OC43, and HCoV-HKU4 with high affinity, but bind to the S protein of HCoV-HKU1 with lower affinity. The gene discussed is PROS1; the disease is COVID-19.