PIK3CA and cancer: When examining the somatic mutations, we found that the top 20 cancer driver genes mutated more frequently in the high-risk group than in the low-risk group, including four tumour suppressor genes (e.g., APC, TP53, LRP1B and ZFHX4) and the other sixteen genes (e.g., TTN, KARS, MUC16, SYNE1, PIK3CA, FAT4, RYR2 DNAH5, RYR1 and FBXW7, etc.)are oncogenes in disease development and progression (Figures 4A,B), and significant co-occurrences were also observed among mutations of these genes (as shown in Figure 4C).