To determine SPHK1 expression levels in ovarian cancer EVs, we first isolated and characterized EVs from culture media of ovarian cancer cells as described before.[10] The isolated EVs were then analyzed by transmission electron microscopy (TEM) and nanoparticle tracking analyzer, which confirmed them to be ≈50–200 nm in size with an average size of 150 nm (Figure S1A,B, Supporting Information). Here, SPHK1 is linked to ovarian cancer.