SPHK1 and cancer: SPHK1/S1P signaling has been linked to cancer progression and metastasis,[3] as it modulates many key oncogenic events, such as proliferation, migration, invasion, adhesion, angiogenesis, and apoptosis.[4] Consistent with these observations, we found elevated S1P levels in high‐grade serous ovarian cancer patients’ plasma and high SPHK1 enzyme expression in tissue samples.