S1PR1 and breast carcinoma: Poor prognosis based on recurrence-free survival (RFS) in breast cancer was significantly correlated with low S1PR1 expression (HR = 0.67, P = 7.1e-13), but a significant correlation was not observed for overall survival (OS) (HR = 0.86, P = 0.17) and post-progression survival PPS (HR = 1.03, P = 0.82) (Fig. 2g–i).