Additionally, anti-beta-arrestin-1 stained positive for all 6 metastatic lung adenocarcinoma in specimens from their metastatic sites, whereas anti-TTF1 and anti-NAPSA unambiguously stained only 2 (from patients 19 and 29) and 3 samples (from patients 22, 19 and 34), respectively (Supplementary Figure 3). Here, TTF1 is linked to lung adenocarcinoma.