Indeed, by using transgenic mouse models that express either ATX or one of the LPA receptors—LPA1, LPA2 and LPA3—under the mouse mammary tumor virus-long terminal repeat (MMTV-LTR) promoter, the authors demonstrated that forced expression of ATX or of one of the three LPA receptors in the mammary glands was sufficient to induce the spontaneous development of breast cancer [52]. This evidence concerns the gene ENPP2 and breast cancer.