Activation of the innate immune function of RIG-I in tumours enhances immune checkpoint inhibitor-mediated cancer immunotherapy (Heidegger et al, 2019a; Heidegger et al, 2019b), promotes lymphocyte infiltration into the tumour, and reduces tumour growth and metastasis (Ellermeier et al, 2013). This evidence concerns the gene RIGI and cancer.