In addition, we observe that four genes (i.e., COL9A1, MSANTD2, LMBRD1 and RP11-1391J7.1) were differentially expressed between normal samples and tumor samples (Additional file 1: Figure S13), and that COL9A1 was differentially expressed among different tumor stages (Additional file 1: Figure S14). This evidence concerns the gene COL9A1 and neoplasm.