APOD and neoplasm: In total, 11 optimal genes (CYTL1, PLCL1, CGB5, ADRA1B, APOD, RGS2, CST6, MATN3, RNF43, SLC7A2 and SERPINE1) were screened (Table 2) and most of the optimal genes were significant differential expression between the normal tissue and tumor tissue (Fig. S4).