We have presented that mutation K15R of LIN28A attenuated its roles in promoting cancer cell proliferation, migration, and 3D cell culture growth (Fig. 3) by retarding its inhibition of mature let‐7 biogenesis (Fig. 4), so we guessed that SUMOylation of LIN28A might also promote cellular transformation and tumorigenesis by enhancing inhibition of let‐7 biogenesis. Here, LIN28A is linked to cancer.