The Hect domain is a specific protein domain found in various proteins, primarily involved in the regulation of gene expression and cellular processes. It is named after the Hect (Homologous to the E6-AP Carboxyl Terminus) protein, which plays a crucial role in tagging proteins for degradation through a process called ubiquitination. Proteins containing the Hect domain often function as E3 ubiquitin ligases, which help transfer ubiquitin molecules to target proteins. This modification can signal for the protein's degradation or alter its activity, thus influencing various cellular functions, including cell cycle regulation and response to stress.