Fig. 2: Skull bone marrow cells access brain-derived solutes via the CSF and supply CNS tumors with HSPCs and myeloid cells.

a, Multiplexed measurement of cytokines and chemokines in CSF of EP^ZFTA-RELA-bearing and control mice using Luminex; n = 6 per group; data are mean ± s.e.m. P values represent two-sided t-tests with Holm–Šídák multiplicity adjustment. b, Experimental design of intracisterna magna (ICM) injections of anti-c-Kit BV421 and OVA-488 into the CSF of tumor- and nontumor-bearing mice (n = 5 per group). c,d, Quantification of ICM-injected c-Kit⁺Lin⁻ Sca-1⁺c-Kit⁺ cells (c) and OVA⁺ macrophages (d) in skull, tibia and dura (n = 5; mean ± s.e.m.; linear mixed-effects model with Wald z-tests and Bonferroni correction, two-sided). e, log₂ fold change of the proportion of intratumoral macrophages, CD8 T cells, HSPCs and neutrophils following intracalvarial AMD3100 (2 mg kg⁻¹, 6 h) or aCSF treatment (n = 5 per group; mean ± s.e.m.; linear mixed-effects model with Wald z-tests and Bonferroni correction) relative to aCSF. f, Design for g–k: CSF transfer from tumor or nontumor mice (n = 4 per group). g, Quantification of CD45⁺ cells in the CSF (mean ± s.e.m.; two-sided Student’s t-test). h–k, Quantification of CD45⁺ neutrophils (h), Ly6C⁻ monocytes (i), HSPCs (j) and B cells (k) in dura, tibia and skull (mean ± s.e.m; linear mixed-effects model with Wald z-tests and Bonferroni correction, two-sided). BM, bone marrow; T, tumor; NT, nontumor. Illustrations in b and f created with BioRender.com.