Transcriptional activator that binds to the RPG box and to telomeres. Involved in the regulation of the transition between yeast and filamentous forms and plays a role in virulence. Induces expression of HWP1, a major hyphal cell protein and virulence factor. Expression is increased in during infection. Expression is also regulated by CDC28, SKO1, and SSK1. Induces filamentous growth and leads to decreased HWP1 expression. Belongs to the RBF1 family.