SphK1 regulates EGFR and STAT3. (A) p-EGFR (Y1173), p-STAT3 (Y705), p-ERK, and p-AKT induced by EGF are greater in SphK1 overexpressing cells compared to mock conditions (Immunoblot). (B) SphK1 transient knockdown reduced EGF-induced EGFR, STAT3, and ERK phosphorylation (Immunoblot). (C) IL-6 levels are significantly greater in media conditioned by SphK1 overexpressing cells versus mock conditions (P < 0.01, ELISA, left). SphK1 knockdown significantly reduced IL-6 concentration in conditioned media as measured with ELISA (P < 0.01, right). Means ± SE are presented, **p < 0.01, ***p < 0.001.