In one such study with 26 patients who have recovered from COVID-19, SARS-CoV-2 S1-targeted antibodies were found in large amounts, but when ELISA inhibition assay was performed to check the efficiency of these antibodies in blocking the interaction between SARS-CoV-2 RBD and hACE2, only 3 of the antibodies out of the 26 collected were successful.95 This observation is extremely important, as we learn from it that though all COVID-19 convalescent patients can produce anti-S1 as well as anti-RBD antibodies, in reality only a fraction of them can actually block the hACE2–RBD interaction. This evidence concerns the gene PSMD1 and COVID-19.