TTF-1 (-) - Absence of Thyroid Transcription Factor 1: Meaning, Applications, & Cancer Diagnosis

TTF-1 (-) refers to the absence of TTF-1 expression in a particular tissue or cell. TTF-1, also known as thyroid transcription factor 1, is a protein that is typically expressed in the thyroid gland, lungs, and certain regions of the brain. It plays a role in the development and function of these organs. When TTF-1 is negative or not expressed, it can indicate the absence of cells or tissues that normally express this protein. In the context of cancer, TTF-1 (-) can be used as a marker to distinguish certain types of tumors. For example, non-small cell lung cancer (NSCLC) is commonly TTF-1 (-), while small cell lung cancer (SCLC) is typically TTF-1 (+). This information can be useful in determining the origin and classification of a tumor when making a diagnosis or planning treatment.