Transcriptional regulator with a general role in all morphogenetically distinct forms of filamentous growth, namely invasive growth and biofilm formation. May control FLO11 gene expression as part of a promoter-bound complex with FLO8 and MSS1. Important for virulence. Interacts with FLO8 and MSS11, both morphogenetic transcription factors binding directly to the FLO11 promoter. Defective in filamentation and invasive growth in response to environmental cues. Defective in the formation of biofilms. Displays decreased virulence in the greater wax moth Galleria mellonella infection model. Belongs to the MFG1 family.