CD44 and glioblastoma: Compared to other tumor types, for which there is a more generalized consensus on the CSC-related markers (such as for CD44+CD24− in breast carcinomas, CD133+ in glioblastomas, and LGR5+ in colon carcinomas, etc.), it is striking to see how heterogeneous the sets of putative OCSC markers are [41], particularly, CD44, CD133, CD117, ALDH1 [42], and the combinations CD44+/CD24−, CD44+/CD117+ [43].