For instance, it promotes GC cell autophagy by targeted down-regulation of Rictor expression to inhibit GC progression [33]; let-7a-5p blocks GC cell cycle progression and inhibits cell metastasis by suppressing RAB40C expression [34]; another study reports that let-7a-5p represses GC cell proliferation, migration and invasion via decreasing PKM2 expression [35]. Here, PKM is linked to gastric cancer.