Out of the lncRNAs with elevated expression and hypomethylation in the L3 subtype, H19 is a molecular marker for GC diagnosis [18, 30] and plays important functions in promoting GC cell proliferation, metastasis [31, 32], DNA hypomethylation [33], genome instability and suppression of p53 activation [21, 34]. The gene discussed is TP53; the disease is gastric cancer.