Genes that satisfy molecular Koch's postulates are often referred to as virulence factors.
[1] As per Falkow's original descriptions, the three postulates are:[1] To apply the molecular Koch's postulates to human diseases, researchers must identify which microbial genes are potentially responsible for symptoms of pathogenicity, often by sequencing the full genome to compare which nucleotides are homologous to the protein-coding genes of other species.
Alternatively, scientists can identify which mRNA transcripts are at elevated levels in the diseased organs of infected hosts.
Additionally, the tester must identify and verify methods for inactivating and reactivating the gene being studied.
[2] In 1996, Fredricks and Relman proposed seven molecular guidelines for establishing microbial disease causation:[3]