In a C4-2B prostate cancer cell line-derived xenograft (CDX) model described in our previous study (16), we detected ABCB1 overexpression at the transcript (Fig. 4C) and protein (Fig. 4D and SI Appendix, Fig. S5A) levels in the tumors at endpoint (day 24), but not at day five (SI Appendix, Fig. S5 B and C). Here, ABCB1 is linked to prostate cancer.