Lung tissues were fixed in 10% buffered formalin solution (pH7.2) for overnight, and serially sectioned to 15 μm at 20ºC. Immunohistochemistry was performed as described.33 (link) Immunoreactivity scores were analyzed using Image Scope V 10.0 software from Aperio Technologies (Vista, CA). The size and number of the metastases were also quantified and counted using Image Scope V 10.0 software (Aperio Technologies, Vista, CA).