In vivo genetic genealogy tracing demonstrated the specific ability of the ABCB5(+) subpopulation to self-renew and differentiate compared to ABCB(-), as ABCB(+) cancer cells produced both ABCB5(+) and ABCB5- progeny, whereas the ABCB5(-) tumor population produced only ABCB5(-) cells (42). This evidence concerns the gene ABCB5 and cancer.