Table 2: Frequencies of specific mutations in PIK3CA. These mutations usually occur within two hotspot-areas within the helical domain (encoded by exon 9) and the kinase domain (encoded by exon 20). Data are according to COSMIC database.
| Exon | Amino Acid Change | Nucleotide Change | Frequency Among PIK3CAMutated Ovarian Cancer |
| 9 | E542K | 1624G>A | 10.2% |
| E545K | 1633G>A | 12.6% |
| E545A | 1634A>C | 12.6% |
| Q546K | 1636C>A | 1.8% |
| 20 | H1047R | 3140A>G | 41.4% |
| H1047L | 3140A>T | 2.8% |