ATYPICAL RESPONDERS LANDSCAPE REVIEW ∙ OCTOBER, 2017 39 Metabolize: to break down. For example, enzymes in the liver break down or metabolize drugs and other foreign substances so that they can be excreted from the body. Metabolism can activate an inactive drug or inactivate an active drug. Microenvironment: the environment in which a tumor is located. The microenvironment consists of a variety of molecules, cells, and blood vessels, all of which may affect the survival of tumor cells and the response to therapy. microRNA: RNA that is transcribed (i.e., the RNA code is used to make a certain protein) from DNA in the cell’s nucleus but that does not encode a protein. microRNAs bind to other RNA molecules called messenger RNA or mRNA that encode proteins and regulate the translation of mRNA into protein. Mitochondria: the part of the cell responsible for energy production Modality: regimen; a series of practices Molecular aberrations: abnormal variations present in DNA that include:  Amplifications and duplications: more copies of a gene or multi-gene region than are normally present Copy number variation: a different number of copies of a gene Deletion: removal of DNA from a sequence Insertion: addition of extra DNA to a sequence Multi-gene fusion: joining of two genes or parts of genes that are not normally found together Mutation: a change in the DNA sequence Rearrangement: a section of DNA that is moved to another location Translocation: swapping the location of genes, often between two different chromosomes Truncation: shortening of a gene Molecular pathways: the stepwise process by which different proteins in one or more cells send a message that changes the status or function of another cell Molecular testing: analysis of DNA, RNA, or protein from a biological sample such as blood or a tumor Monotherapy: treatment with a single drug Neuropathy: when one or more parts of the nervous system are not working properly. Neuropathy generally involves “peripheral” nerves, which are those outside the brain and spinal cord. Symptoms of neuropathy include pain, numbness, and weakness.