Given that the amount of ACE2 on the cell surface is positively correlated to the viral infection whether it is in the scenario of pseudovirus or authentic virus (SI Appendix, Fig. S7), and the cell surface protein level of ACE2 is tightly controlled by SNX27 (Fig. 2), we therefore normalized the cell surface protein level of ACE2 in order to eliminate the variation of ACE2 resulting from the SNX27 disturbance. The gene discussed is ACE2; the disease is viral infectious disease.