To confirm the importance of the STING pathway and to determine whether host or cancer cell STING status has a more dominant role in PC7A-induced antitumour immunity, we performed a tumour growth inhibition assay in host Tmem173−/− (which encodes STING) mice + wild-type (WT) MC38 tumours and WT mice + Tmem173−/− MC38 tumours (Supplementary Fig. 12a–c). Here, STING1 is linked to cancer.