AHR and neoplasm: To determine if AHR, which increases expression of stem cell-associated properties in vitro, influences tumor cell fate in vivo, SUM149 cells, stably transduced with a dox-inducible shAhr (Fig. 8), were sorted and 3,000 ALDHhigh and ALDHlow cells were injected into the right and left mammary fat pads, respectively, of female NOD/SCID mice.