PPBP and aneurysm: Figure 6A illustrates the expression of statistically significant hub genes. To further validate the hub genes, the mRNA levels of these hub genes (APP, JUN, GSK3B,ErbB2, PPBP and THBS1) in 6 samples are determined, and the results are consistent with previous findings. As illustrated in Figure 6B, the level of THBS1, PPBP, and JUN expression is elevated and the expression of APP, GSK3B and ErbB2 is significantly lower in patients compared with controls. These results confirm that six hub genes are potential biomarker for ruptured aneurysms (Figure 7).