Fig. 3: rCap markers are enriched in ECs in metastatic lungs.

Visualization of reactive capillary endothelial cell (rCap) markers Pim3 (a), Inhbb (b) and Bcl3 (c) expression in the integrated scRNASeq data from mouse lungs, 6 h post intravenous (i.v.) injection of B16-F10 melanoma cells or PBS (Ctrl). n = 3 independent experiments. d, e Representative images of RNAscope^TM in situ hybridization (ISH) and immunohistochemistry of lung sections from similarly injected mice. Pim3 (d, e), Bcl3 (d), Inhbb (e), and Pecam1 (d, e) were detected using ISH, melanoma cells using anti-PMEL antibody and nuclei by DAPI. n = 3 mice per group. Quantification of Pim3 (f), Bcl3 (g) and Inhbb (h) signal area in the lungs, normalized to nuclear area, relative to Ctrl. n = 3 mice per group. i–l Representative higher magnification images from samples in (d, e), showing coexpression of Pim3 with Bcl3 (i) or Inhbb (k) transcripts near cancer cells. Quantification of Pim3⁺Bcl3⁺ (j) and Pim3⁺Inhbb⁺ (l) double positive Pecam1⁺ cells normalized to all Pecam1⁺ ECs from Ctrl and 6 h B16-F10 lung. n = 3 mice per group. m, n Quantification of PIM3 protein levels in ECs isolated from Ctrl and 7 h B16-F10 i.v. injected mouse lungs, normalized to GAPDH. n = 4 mice per group. Wilcoxon rank-sum test (a–c), two-tailed unpaired t-test (f–h, j, l, m). Data are presented as mean values ⁺/- SD. Scale bars 25 μm (d, e) and 5 μm (i, k). Source data are provided as a Source Data file.