Definition

One of a group of proteins that play an important role in controlling the activity of genes. Transcription factors help control when and how genes are turned on or off in a cell by binding to nearby DNA and to other DNA-associated proteins. This affects the production of RNA, which then affects the production of proteins and their many important cell functions. Mutations and other changes in transcription factor genes may cause abnormal transcription factor proteins to be made. These abnormal proteins may be too active or found in higher-than-normal amounts on or in some types of cancer cells, which may cause the cancer cells to grow. Drugs that block transcription factor proteins and proteins associated with them are being studied in the treatment of some types of cancer.