PROM1 and cancer: Cluster 1 highly expressed ICAM-1 (CD54) and vimentin, positively expressed cancer stem cell markers CD90 and LGR5 [22,23]; Cluster 2 characteristics of high levels of CD47, Notch 2, vimentin, CD90, LGR5, Sox2; Cluster 3 exhibiting high levels of PD-L1, androgen receptor (AR), bladder cancer stem cell markers CD133, ALDH [24,25]; Cluster 6 was characterized by high levels of PD- L1, ALDH, and lacked expression of ER-β.