 Powdery mildew and rust fungi are two types of pathogenic fungi that cause severe damage to plants. These fungi use specialized structures called haustoria to gain access to the plant's tissues and steal nutrients. To protect themselves from the plant's defences, the fungi produce a variety of effector proteins that are secreted into the plant cell through the haustoria. One type of protein called YFWXC proteins has been found to be particularly abundant in the haustoria of both powdery mildew and rust fungi. These proteins are composed of a small number of amino acids, including tyrosine, phenylalanine, tryptophan, and cysteine, all of which are arranged in a specific order, YFWXC. This unique arrangement suggests that the YFWXC proteins may play important roles in the interaction between the fungus and its host plant. This article was authored by Emerson Yeppie, Jong Zegwa, Pedersen Casten, and others. We are article.tv, links in the description below.