For example, although ALDHs are present in most human tissues and represent a CSC marker for several cancer types, their activities play no functional role in stem cell-like properties in anaplastic thyroid cancer cells.383 Also, the CSC markers, CD133 and CD44, are generally overexpressed in gastrointestinal stromal tumors (GISTs) and cannot be used to distinguish CSCs from non-CSCs.384. This evidence concerns the gene PROM1 and cancer.