Immunohistochemistry

The tumor samples and the paired normal samples in our hospital were patients suffering from LUAD or LUSC. Tissue sections were deparaffinized, rehydrated, and permeated using Triton X 100 (T8200, Solarbio, Beijing, China) and followed by antigen retrieval using EDTA Antigen Retrieval solution (c1034, Solarbio, Beijing, China). The sections were incubated with Anti-CAV1 antibody (ab32577, Abcam, UK), Anti-CAV2 antibody (ab79397, Abcam, UK), Anti-CAVIN1 antibody (ab48824, Abcam, UK), Anti-CAVIN2 antibody (ab76867, Abcam, UK), Anti-CAVIN3 antibody (ab179923, Abcam, UK) at 4 °C overnight followed by a biotinylated secondary antibody (diluted at 1:200) at RT for 60 min. Then, the sections were stained with DAB staining solution (AR1022, BOSTER Biological Technology, Wuhan, China). To quantitatively evaluate the expression levels of each protein in the samples from patients with LUAD and LUSC, we calculated the percentage of cells stained. The extent of staining was scored as the following criteria: (a) percentage of stained cells: 0 (0%), 1 (1%-25%), 2 (26%-75%), 3 (51%-75%), and 4 (> 75%); and (b) staining intensity: 0 (negative staining), 1 (low staining), 2 (medium staining), and 3 (high staining). The final scores were calculated by multiplying the scores of intensities with that of extent.