IRF1 and colorectal cancer: DiScala et al. (2020) found that loss of STAT6 results in trastuzumab resistance in HER2+ breast cancer cells. IRF1 functions in immune response, DNA damage, and DNA repair. IRF1 is downregulated in colorectal cancer and suppresses cell proliferation, migration, and metastasis (Hong et al., 2019). Moreover, in RCC, IRF1 can inhibit Ki-67 gene transcription by interfering with Sp1 activation (Chen F et al., 2012).