In addition, it was revealed that in Lin28A overexpressed in human embryonic stem cells or cancer cells, the 3′-terminus of pre-let-7 is oligonucleotidylated by TUT4 and TUT7 to produce a uridine tail of approximately 14 nt, which resists Dicer cleavage but is readily degraded by the cytoplasmic exosome DIS3L2 catalytic (Figure 2c) [47,48,49,50,51]. The gene discussed is DIS3L2; the disease is cancer.