Secretion of IFNβ1 by CTX‐treated cancer cells led to an antiviral response in stromal fibroblasts, associated with the expression of several ISGs such as DExD/H‐Box Helicase 58 (DDX58), interferon Induced with Helicase C Domain 1 (IFIH1), interferon‐stimulated protein, 15 KDa (ISG15) and 2'‐5'‐Oligoadenylate Synthetase 1 (OAS1). This evidence concerns the gene OAS1 and cancer.