ARHGEF15 and cancer: Not surprisingly, similarity among different cancer types was identified in only 6 out of 23 clusters, including E3 (IRS2, KRT6A), E5 (CD24, STMN1), E8 (GKN1, MUC5AC), E9 (PHGR1, TFF3), E10 (TFF3, TPO) and E13 (VTN and ITIH5) (Supplementary Fig. S2c, d).