High mRNA expression of OAS1 (HR = 2.01, 95%CI: 1.26–3.18, p = 0.0026), OAS3 (HR = 1.72, 95%CI: 1.13–2.64, p = 0.011) and OASL (HR = 1.8, 95%CI: 1.17–2.77, p = 0.0066) was significantly associated with worse OS in grade 2 breast cancer. Here, OAS1 is linked to breast cancer.