PIK3CA and cancer: In the second dataset, LUSC, PIK3CA (46.5%), EGFR (7%), PDE4DIP (6.6%), KRAS (4.4%), and RELN (4.4%) were labeled with copy number gain, while CDKN2A (27.9%), LRP1B (17.4%), PTEN (9.8%), and PTPRD (9%) appeared to be the cancer genes with copy number loss (Figure 2).