The NOT family is a group of proteins involved in transcriptional repression, including members such as NOT1, NOT2, NOT3, and others. They are structured with multiple functional domains and are primarily located in the cell nucleus. NOT family proteins are core components of the CCR4-NOT complex, which is involved in RNA degradation and transcriptional regulation. By interacting with other proteins such as CCR4 and CAF1, the NOT family influences mRNA stability and post-transcriptional processing, thereby regulating gene expression. The expression of NOT family proteins is tissue-specific, and mutations or dysregulation in their gene expression are associated with various diseases, including cancer, neurodegenerative diseases, and developmental abnormalities.