To investigate the role of fibroblast ATM targeting in immunocompetent mouse models, and to overcome the issue of low CAF content in commonly used syngeneic murine tumors, we used a syngeneic isograft lung cancer model as described previously (14), coinjecting TC-1 cancer cells with TGFβ1-treated MLF, which recapitulates the myoCAF-rich stroma of human tumors (Supplementary Fig. S5A–S5C). Here, ATM is linked to cancer.