Fig. 1

A mouse model of PIK3CA-related capillary venous malformations. a Representative photography of PIK3CA^WT and PIK3CA^Tie2-CreER mice 4 weeks after Cre recombination. b Kaplan–Meier survival curves of PIK3CA^WT and PIK3CA^Tie2-CreER mice (n = 25 per group). c Coronal whole-body T2-weighted fat saturated magnetic resonance images (MRI) of PIK3CA^WT and PIK3CA^Tie2-CreER mice (n = 4–6 mice per group) 5 weeks after Cre recombination. Volumetric quantification of the vascular malformations. d Representative hematoxylin and eosin (H&E) staining of the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice and patient with venous malformation (VM). Large irregular and dilated vessels filled with red blood cells were visible in the skin of PIK3CA^Tie2-CreER mice. Scale bar: 40 μm. e Representative coimmunofluorescence staining of Tie2 and GFP in the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice. Scale bar: 10 μm. f GFP is express in CD31+ cells as assessed by flow cytometry experiments of cells isolated from the skin of PIK3CA^WT (n = 4 mice). g GFP and podoplanin staining using flow cytometry experiments of cells isolated from the skin of PIK3CA^WT (n = 4 mice). h Representative immunofluorescence staining of P-AKT^Thr308 and P-S6RP in the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice. Scale bar: 10 μm. i Western blot and j quantification of P-AKT^Ser473 and P-S6RP in the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice (n = 5–8 mice per group). k Flow cytometry experiments showing the percentage of GFP + CD31+ cells isolated from the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice expressing P-AKT^Ser473 (n = 6–7 mice per group). l Representative immunofluorescence staining of KI67 in the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice. Scale bar: 10 μm and m quantification (n = 4 mice per group). n Flow cytometry experiments showing the percentage of GFP + CD31+ cells isolated from the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice expressing KI67 (n = 3–4 mice per group). o Flow cytometry experiments showing the percentage of Tomato+ cells isolated from the skin of PIK3CA^WT and PIK3CA^Tie2-CreER mice expressing KI67 (n = 3–4 mice per group). p Quantification of GFP positive cell surface isolated from PIK3CA^WT and PIK3CA^Tie2-CreER mice (n = 5 mice per group). q Complete blood count and D-Dimers measurement in PIK3CA^WT and PIK3CA^Tie2-CreER mice (n = 11 per group)