obsolete abnormal effector of virulence activation of host defense 2018-10-18T13:25:51Z true The pathogen has the ability to cause infectious disease dependent upon the gene for gene relationship between the pathogen and host genotype and this is altered compared to the wildtype interaction. This may result in disease (virulence) or no disease (avirulence). pathogen_host_interaction_phenotype alaynecuzick