A laboratory test in which many genes are studied in a sample of tissue. Multigene tests may help find mutations (changes) in certain genes that may increase a person’s risk of a disease such as cancer. They may also look at the activity of certain genes in a sample of tissue. Multigene tests may be used to help plan treatment or make a prognosis, including helping to predict whether cancer will spread to other parts of the body or come back. Also called multiple-gene panel test and multiple-gene test.