Biosynthetic pathway of melanin in A. fumigatus. White mutants obtained by Brakhage  and Kwon-Chung  had mutations in the ALB1 (also called PKSP) gene. Steps inhibited by commercialised DHN-melanin inhibitors are localized (Tc, tricyclazole; Pq, pyroquilon; Fx, fenoxanil). 1,3,6,8-THN, 1,3,6,8-tetrahydroxynaphthalene; 1,3,8-THN, 1,3,6,8-trihydroxynaphthalene; DHN, dihydroxynaphthalene (adapted from Tsai et al. ).