IFNAR1 and cancer: Type I IFN have been shown to be dispensable for RLR-induced apoptosis, although the cancer-specific mechanism was not clear.24 It has been reported that MDAMB-231 cells lack IFNAR1.11, 12 We found that the ectopic expression of IPS-1 in the MDAMB-231 cells delayed wound healing and reduced the number of colonies, as indicated by the WHA and colony-formation assay, respectively.