MBTPS1 and ovarian cancer: Interestingly, neutralizing S1P, the product of SPHK1 enzymatic activity, with a specific monoclonal antibody was remarkably effective in slowing progression of cancers, such as lung [40], colon [41], breast [42,43], melanoma [44] and ovarian cancers [21,45] in murine xenograft and allograft models [46].