Based on the therapeutic mechanisms, we classified the remaining therapies, corticosteroids, PD-1/PD-L1 checkpoint inhibition, cytokine-adsorption devices, intravenous immunoglobulin, and antimalarial agents, as “less potential treatments.” No literature of COVID-19 except for corticosteroids mentions the effectiveness and safety of the less potential treatments. Here, CD274 is linked to COVID-19.