Acyl-coenzyme A: cholesterol acyltransferase (ACAT)2 is a cholesterol esterification gene that is upregulated in statin-resistant MCF10.DCIS cells, and in mammary tumors of statin-non-responsive SV40 C3(1) TAg mice. The gene discussed is SOAT1; the disease is ductal breast carcinoma in situ.