AXL and breast cancer: To establish the method for detecting AXL‐expressing cancer cells using preclinical models, we examined the expression levels of AXL, epithelial marker CK, and mesenchymal marker VM by immunofluorescent staining (Figure 1A) and immunoblotting (Figure 1B) in NSCLC cell lines PC‐9, HCC827, and H1299 and breast cancer cell line MDA‐MB231.