According to established principles for evaluating immunostaining, the expression of DRAM2 was negative in the normal alveolar (Fig. 1A-a), and negative or very weakly positive in the normal bronchi (Fig. 1A-b), but relatively higher in squamous carcinoma tissues (Fig. 1A-c) and adenomatous carcinoma tissues (Fig. 1A-d). This evidence concerns the gene DRAM2 and squamous cell carcinoma.