Of these, high expression of S1PR1 (HR = 0.64, 95% CI: 0.58–0.72, p = 7.2e-16) and S1PR4 (HR = 0.81, 95% CI: 0.73–0.91, p = 0.00023) was significantly associated with better RFS in all patients with BC (Figure 2). This evidence concerns the gene S1PR4 and breast cancer.