Here, we describe molecular and clinical findings related to the breast cancer cell lines SV-BR-1 (Saint Vincent’s Breast Cancer cell line 1) and SV-BR-1-GM (SV-BR-1 stably transfected with CSF2, encoding granulocyte-macrophage colony-stimulating factor (GM-CSF)). The gene discussed is PPP1R3A; the disease is breast cancer.