The invention relates to the therapeutic or prophylactic treatment of fungal infections. The invention provides new methods for therapeutically or prophylactically treating fungal infections using sub-lethal concentrations of an anti-invasin compound. The methods according to the invention have fewer toxicology problems than existing methods, and thus can be used prophylactically, as well as for early treatment for high risk patients without a firm diagnosis. The methods according to the invention can also be used to treat an established fungal infection. The invention further provides novel genes that regulate fungal hyphal growth.