CD68 and adenocarcinoma: In subgroup analyses, adenocarcinoma NSCLC patients with high CD68 expression (log-rank p = 0.034) showed a significant survival advantage (Additional file 2: Fig. S4a), whereas adenocarcinoma NSCLC patients with high M2 ratio (log-rank p = 0.047) had poor survival (Additional file 2: Fig. S4c).