ALDH1A1 and breast cancer: Indeed, sphingolipids, such as sphingosine-1-P (S1P), eicosanoids, such as prostaglandin E2 or glycerophospholipids, such as lysophosphatidic acid (LPA), have been reported to increase CSCs proliferation and in vivo tumorigenicity, activating self-renewal and survival signaling pathways (Notch, AKT, NF-kB) in ALDH1+ from breast cancer, label-retaining cells in bladder cancer, CD133+CD44+ cells in CRC and sphere-derived cells from ovarian cancer (Hirata et al., 2015; Kurtova et al., 2015; Wang et al., 2015; Seo et al., 2016).