Our results raise the possibility that the use of an OAS family activator, or less specific inducers of the interferon response, could reduce the pro-metastases pathology that occurs in a significant number of breast cancers during pregnancy, the immediate postpartum period and in cases expressing the involution-mimicry phenotype, and that efficacy could be increased by combination with checkpoint immunotherapy. The gene discussed is SMOC1; the disease is breast cancer.