Following orthotopic implantation of 10 cells into mouse mammary fat pads, ICAM1 OE significantly increased the tumorigenicity of TN1 PDX, elevating the TIC frequency from one in 133 ICAM1− cells to about one in 15 ICAM1+ cells (Supplementary Fig. 2d–h); however, the tumor initiation or growth from 100 to 1000 cell implants had relatively smaller differences between the two groups (Supplementary Fig. 2d–k). Here, ICAM1 is linked to neoplasm.