In contrast, endogenous nuclear IRF3 levels or expression of IRF3 target genes did not increase in human DU145 prostatic carcinoma cells, A549 lung carcinoma cells, HeLa cervix carcinoma cells, and HCT116 colorectal carcinoma cells in response to ISD or cGAMP (Fig. 1A and B). Here, IRF3 is linked to colorectal carcinoma.