Non-inflamed human tumors lack type I IFNs, which are important in both innate and adaptive immune-mediated tumor eradication.53 IFN-α and IFN-β enhance tumor antigen presentation and increase cytotoxic killing of tumor cells.34 Despite a promising 20–40% response rate in pilot studies with human leukocyte IFN (a mixture of IFN-α subtypes), subsequent monotherapy studies in advanced breast cancer patients were unsuccessful.54 There is one ongoing clinical trial using IFN-α with pembrolizumab and a therapeutic breast cancer vaccine (NCT03328026) in metastatic breast cancer. Here, IFNA1 is linked to breast cancer.