At the same time, lungs were immunostained or labelled in vivo using antibodies against protein markers of each cellular component in the tumour microenvironments (Fig. 1c, d): α-smooth muscle actin (α-SMA) for vascular smooth muscle cells, vascular endothelial growth factor receptor-3 (VEGFR3) for lymphatic endothelial cells, ionized calcium binding adapter molecule 1 (Iba1) for activated macrophages, and cluster of differentiation 42c (CD42c) for platelets. This evidence concerns the gene FLT4 and neoplasm.