To identify new alphavirus receptors, we first generated a reporter virus rGETV-mCherry with mCherry inserted immediately downstream of the furin cleavage site between E3 and E2 regions of the structural polyprotein (Supplementary Fig. 1a), so that the infection efficiency of rGETV-mCherry can be monitored by fluorescence microscopy analysis of mCherry expression (Supplementary Fig. 1b) and additionally verified by western blot analysis of the expression of E2-mCherry fusion protein and its precursor (Supplementary Fig. 1c). The gene discussed is FURIN; the disease is infection.