PIWIL4 and cancer: A manual online search into two medical e-databases PUBMED and google scholar for (“piR-823” OR “piRNA-823”) AND (“piR-823 in Cancer”) AND (“piRNA in Cancer”) AND (“in silico”) AND (“Cancer hallmarks”) AND (“SNPs”) AND (“Piwi proteins”) AND (“Prognostic marker”) AND (“Diagnostic marker”) AND (“Nanoparticles”) AND (“Exosomes”) was done on June, 2023.