Lin28 is a cytoplasmic, RNA-binding protein that is highly expressed both in embryonic stem cells, where it regulates cell growth [32], and in several cancers where it interferes with the maturation of members of the let7 family of miRNAs [33]–[35], which regulate Hmga2 and downstream targets such as Snai1 that promote metastasis and invasion [36]–[39]. The gene discussed is SNAI1; the disease is cancer.