Extended Data 2. Pro-inflammatory cytokine status, vessel permeability and BM DTC seeding in NG2+/Nestin+ MSCs-depleted mice.

a. Levels of pro-inflammatory cytokines in BM supernatant of WT and NG2-CreERiDTR mice (n=13 WT and 11 iDTR mice, from 2 independent experiments, median and interquartile range, 2-tailed Mann–Whitney tests, *p≤0.05, n.s. not significant, n.d. not detected). b-d. NG2-CreERiDTR mice (NG2-CreER- or +) were daily i.p. injected with tamoxifen for 5 days followed by a rest day and 2 i.p. injections of DT. E0771-GFP cells were intra-cardiac injected and 24 hours after 70K Dextran-TexasRed was injected 15 minutes prior euthanasia. c. Representative images of Dextran extravasation in perfused bones. Arrows, E0771-GFP cells. d. Number of E0771-GFP cells detected after 1 week of in vitro expansion of the BM aspirates collected 24 hours after injection into mice (n=5 WT and 5 iDTR mice, median). e-f. NG2-CreERiDTR mice (NG2-CreER- or +) were daily i.p. injected with TAM for 5 days, followed by intra-cardiac injection of E0771-GFP cancer cells. Cells were allowed to disseminate and extravasate for 72 hours followed by 2 i.p. injections of DT. f. Number of E0771-GFP cells/million BM cells (n=5 WT and 5 iDTR mice, median and 2-tailed Mann–Whitney tests, p=0.015). *p≤0.05 (p-values indicated above), n.s. not significant.