Another regression model developed by our lab (in collaboration with Dr. Stephen Young, UCLA) is the Reversa mouse (Ldlr−/− Apob 100/100 Mttp fl/flMx1Cre+/+) (121, 122), where after plaque progression occurs while the mice are on WD, polyinosinic-polycytidylic (pIpC) injection induces the Mx1-Cre gene leading to the inactivation of the microsomal triglyceride transfer protein (MTTP) gene. This evidence concerns the gene MTTP and Wilson disease.