This gene is a member of the carboxylesterase (CES) gene family. The family members are responsible for the hydrolysis or transesterification of various xenobiotics, such as cocaine and heroin, and endogenous substrates with ester, thioester, or amide bonds. They may participate in fatty acyl and cholesterol ester metabolism, and may play a role in the blood-brain barrier system. This gene does not encode a protein and the sequence is similar to the CES1 gene, so represents a pseudogene of the CES1 gene. [provided by RefSeq, Jun 2010].