E2F1-induced LINC00668 is overexpressed in human gastric cancers; it has been found in PRC2 complexes and thereby has been considered responsible for the epigenetic repression of several CDKIs, including p15INK4b, p16INK4a, p21Cip1/Waf1, p27Kip1 and p57Kip2 [270]. This evidence concerns the gene CDKN1A and gastric cancer.