This study integrated clinical and computational analyses to investigate the expression pattern and functional relevance of P-element-induced wimpy testis (PIWI)-interacting RNA-823 (piR-823) and its associated protein piwi-like RNA-mediated gene silencing 1 (PIWIL1)/DNA methyltransferase 3B (DNMT3B)/E-cadherin (CDH1) axis in OC tissues from 40 patients, with 20 non-cancer control samples. This evidence concerns the gene PIWIL4 and cancer.