CUL2 and infection: To explore the essential role of Cul2 in the fly defense against bacterial pathogens, we infected the Cul2 LOF mutants, the key LOF mutants, and the w1118 control flies with Ecc15 or S. marcescens. The Cul2 LOF mutants exhibited a higher mortality rate compared to the w1118 control flies upon infection with either bacterial species (Figure 2A,B).