We established nine HER2-positive breast cancer cell lines expressing the luc2 gene—UACC-893, MDA-MB-453, HCC-2218, BT-474, ZR-75-1, UACC-812, MDA-MB-361, HCC-202, and HCC-1419 cells—with lentiviral vectors (Table S1), and these cell lines were intracranially injected into NOD-SCID mice (HCC-1419 and HCC-2218 cells, n = 4; other cell lines, n = 3). Here, ERBB2 is linked to hepatocellular carcinoma.