CD24 and Patent ductus arteriosus: While uncertainty exists about true nature of CSCs and their role cancer proliferation, in PDA, CSCs have been identified as being CD44+CD24+ESA+, CD133+/CXCR4+, or ALDHhighCD44+CD24− cells [66,67,68], where these cells are highly tumorigenic, promote metastatic spread, and are associated with poor survival.