Ten proteins (CD5L, GNPDA for lung adenocarcinoma, ACAN, C7, DMP1, HEPH for squamous cell carcinoma, CEACAM6, COX6B1, CPXM2, IL12RB2 for small cell carcinoma) were classified into tier 3 (Figure 1). The gene discussed is CEACAM6; the disease is small cell carcinoma.