Glutathione S-transferase theta 2, also known as GSTT2, is member of the glutathione s-transferase (GST) family of proteins. There are eight families of GST proteins, namely alpha, kappa, mu, omega, pi, sigma, theta and zeta, each of which is composed of proteins that have a variety of functions throughout the cell. The theta class members GSTT1 and GSTT2 share 55% amino acid sequence identity and both are thought to have an important role in human carcinogenesis.