The importance of SphK/sphingosine-1-phosphate in oncogenesis, and its potential as a therapeutic target in breast and other cancers, has been studied extensively (21, 22), and a recent study in a metastatic TNBC cell model (23) has confirmed our earlier observations that SphK inhibition decreases EGFR-dependent cell proliferation and survival. This evidence concerns the gene SPHK1 and cancer.