Sequencing is the process of determining the order of base-pair sequences (called nucleotides) within a DNA molecule. Applied to clinical practices, sequencing is used to identify and analyze changes in the genetic material of a tumor. Cancer is considered a genetic disease because the DNA of a normal cell is altered, disrupting certain pathways that control growth and proliferation (division). Changes to DNA can be inherited, but typically they result from errors in the transcription process that occur during cell division, a reduced ability to repair damaged DNA, or exposure to DNA-damaging agents. Sequencing can help physicians recommend the most appropriate treatment course and identify protein for targeted therapies