However, in our hands, knockdown of c-Myc in the Mvt-1 and 6DT1 cell lines has resulted in substantial cell death, which is presumably due to the fact that both cell lines originate from mammary tumor explant-cell cultures derived from the MMTV-c-Myc transgenic mouse model of mammary tumorigenesis [27]. The gene discussed is MYC; the disease is breast cancer.