Mouse and human cancer cell lines, including CT-26 (mouse colorectal carcinoma), U251 (human glioblastoma) (Fig. 2A), SKOV-3 (human ovarian carcinoma) and HT-29 (human colorectal carcinoma) (Supplementary Fig. 1b) were infected with oFV-TK or control oFV at MOI = 1, or mock control. Here, TKT is linked to cancer.