Using VE-cadherin as a VM biomarker20, we assessed its expression in SCLC cytokeratin (CK)-positive CTCs using ISET (isolation by size of epithelial tumour) microfiltration of patient blood samples that captures cells larger than 8 μm (median SCLC cell size 12.5–14.1 μm (ref. 27); Fig. 1). The gene discussed is CDH5; the disease is small cell lung carcinoma.