CDKN1A and neoplasm: We also found a large number of cell cycle genes to be downregulated in the miR-34a-high tumor cell line including the well-known miR-34a target gene Ccne2 [9, 25, 27] and many genes involved in the induction of cell cycle arrest such as p21/Cdkn1a or Gas2l3 whose depletion has been shown to induce genomic instability [48].