While few functional studies have been carried out in whole animals, it has been shown that Trim33 can act in combination with the close homologues, Trim24 and Trim28; Lox-Cre knockdown of Trim33 in the liver of mice null for Trim24 results in increased expression of the VL30 class of retrotransposons [10] and hepatocellular carcinoma [11]. The gene discussed is TRIM33; the disease is hepatocellular carcinoma.