PROS1 and infection: The peptide, spanning from the residue 1168 to 1203, was first conjugated at the C-terminal end with a segment offering the cysteine residue; then, the 42 amino acids produced peptide was attached to a cholesterol moieties, displaying very strong potentialities in: (i) inhibiting cell-cell fusion by the S protein; (ii) reducing live SARS-CoV-2 infection in Vero E6 cell type; (iii) blocking the infection of a broad range of coronaviruses, including SARS-CoV-1 and MERS; (iv) preventing SARS-CoV-2 spread also in ex vivo model, such as human airway epithelial (HAE) cells.