Transcription regulator that functions in both the positive and negative regulation of filamentous growth, depending upon the environmental conditions. Recruits the TUP1/SSN6 general repression complex to achieve repression. Regulates genes encoding cell wall components that are specifically expressed in the filamentous forms such as HWP1, RBT1, HYR1, ECE1, ALS1, RBT4 and RBT5. Expression is regulated by WOR1. Leads to constitutive hyphal growth and avirulence in a mouse model.