CircRNAs highly expressed in exosomes can be transferred from tissues into various body fluids and are potential diagnostic biomarkers for PCa.336 Has-circ-0044516 shuttled by exosomes induces tumor cell metastasis and inhibits tumor cell apoptosis by sponging miR-29a-3p.337 Exosomal circ-XIAP is upregulated in docetaxel-resistance PCa cells and promotes docetaxel resistance by targeting miR-1182/TPD52 axis.338. The gene discussed is XIAP; the disease is posterior cortical atrophy.