MYC and neoplasm: Our earlier work had shown that subcutaneous inoculation of plasmids expressing the human T24-H-ras oncogene and mouse c-myc proto-oncogene, each under control of the murine sarcoma virus (MSV) long terminal repeat (LTR), induced tumors in both adult and newborn immunocompetent mice, with newborns being more sensitive than adults, although the efficiency of tumor induction was low [5].