• A marine-derived cyclic peptide with potent anticancer activity by targeting eEF1A2 (Kd = 80 nM). Plitidepsin also exhibits antiviral activity, notably against SARS-CoV-2 with an IC₉₀ of 0.88 nM. It is primarily used in studies related to multiple myeloma, advanced solid tumors, and emerging viral diseases including COVID-19.