We observed a site‐dependent reduction in CXCR4+ target cancer cell fraction (CXCR4+ CCF) in Mets foci at the end of T22‐GFP‐H6‐FdU treatment, as detected by anti‐CXCR4 IHC, (and as compared to basal levels) which correlated with the antimetastatic effect at the different sites in both SW1417 and M5 patient‐derived CRC models (Fig 6B, Appendix Fig S8B, and Table 1). The gene discussed is CXCR4; the disease is colorectal carcinoma.