Definitions for homozygous and hemizygous p16/CDKN2A deletion determined by fluorescence in situ hybridisation (FISH)
| p16/CDKN2A deletion pattern | FISH signal pattern | Cut-off value for % nuclei with FISH signal pattern | |
| p16/CDKN2A (SpO) | CEP-9 (SpG) | ||
| Homozygous | No p16/CDKN2A signal 0SpO | At least one CEP-9 signal 1-2SpG | >10% |
| Hemizygous | One p16/CDKN2A signal 1SpO | Two CEP-9 signals 2SpG | >15% |
| Hemizygous (monosomy) | One p16/CDKN2A signal 1SpO | One CEP-9 signal 1SpG | >44% |
SpO, Spectrum Orange; SpG, Spectrum Green.