Zygomycota do not face particular challenges and are an extremely abundant phylum. Instead I will talk about the possible harmful effects they have on humans. Within the phylum there are a few organisms that are the cause of several human diseases. The spores from these molds are transmitted by inhalation, or by ingestion of spores. Zygomycosis, infections caused by organisms of the phylum zygomycota, are generally found in immunocompromised hosts. Infection usually occurs in hosts who already had one or more of the following risk factors: diabetes mellitus, neutropenia, sustained immunosuppressive therapy, chronic prednisone use, iron chelation therapy, broad-spectrum antibiotic use, severe malnutrition, and primary breakdown in the integrity of the cutaneous barrier such as trauma, surgical wounds, needle sticks, or burns. Zygomycosis occurs only rarely in immunocompetent hosts.