An intact cell wall structure has been implicated in the complex infection process of F. oxysporum (Schoffelmeer et al., 1999) and mutations in some of the CHS genes led to defect in cell wall structure and loss of pathogenicity of F. oxysporum on their host plants (Madrid et al., 2003; Martín-Udíroz et al., 2004; Martín-Urdíroz et al., 2008). The gene discussed is LYST; the disease is infection.