CD44 and renal carcinoma: CD105, CD29, CD44, CD73, CD90 and NESTIN were positively correlated with 13-gene scores in renal cancers (Fig. S4); an observation which is consistent with these genes being markers of renal CSCs.34 Seven and four CSC markers were positively correlated with 13-gene scores in liver and stomach cancers respectively (Fig. S4).