SIGLEC1 and ovarian neoplasm: Significantly higher fluorescence intensity of CD169+ macrophages was seen in ovarian tumour tissues collected from mice that had been treated with placental micro-EVs (Figure 4A), compared with those collected from mice treated with placental nano-EVs (Figure 4B) or control mice (Figure 4C), as determined by semi-quantitative analysis (Figure 4D, P=0.0286, Mann–Whitney test).