SPHK1 and breast carcinoma: Subsequently, accumulating evidence reveals that PAEs also facilitate breast cancer progression through molecular mechanisms independent of classical ER-mediated pathways, such as promoting the onset of breast cancer tumors via the AhR/HDAC6/c-Myc signaling pathway [22], enhancing the expansion of breast cancer stem cells through the SPHK1/S1P/S1PR3 signaling transduction pathway [23], or promoting the progression of breast cancer by inducing the expression of lymphoid enhancer-binding factor [24].