Analysis of the genome-wide gene expression profile of the organ-preferential metastasis of the human SCLC cell line SBC-5 in mice identified early growth response 4 (EGR4), which was significantly upregulated in bone metastatic tumors (p<0.001, ratio; 2.22) compared with other organ metastases (lung, kidney and liver) [7]. This evidence concerns the gene EGR4 and small cell lung carcinoma.