Gene Ontology (GO) is a controlled vocabulary used to describe the biology of a gene product in any organism. The hypergeometric distribution is a discrete probability distribution that describes the number of successes in a sequence of n draws from a finite population without replacement. Metastatis is the spread of a cancer to different parts of the body from the original (or primary) tumor. Epithelial-mesenchymal transition (EMT) is a program of development of biological cells characterized by loss of cell adhesion and increased cell mobility.