The present invention relates to a method of increasing resistance against fungal pathogens of the family Phacopsoraceae in plants and/or plant cells. This is achieved by increasing the expression of a CASAR protein or fragment thereof in a plant, plant part and/or plant cell in comparison to wild type plants, wild type plant parts and/or wild type plant cells. Furthermore, the invention relates to transgenic plants, plant parts, and/or plant cells having an increased resistance against fungal pathogens, in particular, pathogens of the family Phacopsoraceae, and to recombinant expression vectors comprising a sequence that is identical or homologous to a sequence encoding a CASAR protein.