# Somatic data

[Somatic VCFs](vcf_samples.md) detected as somatic only (tumor minus normal) are analysed for [mutational signatures](mutational_signatures.md)

## Allele Frequency

If the VCF contains an "AF" value, we will use that. Otherwise we will 

We do not import the AF value from the VCF, but instead [normalize](../vcf_samples.md#VCF Normalization) the data then recalculate AF to be ```AD / sum(AD for all variants at locus)```

In an analysis, nodes that represent one or more VCF samples (Sample, Cohort and Trio nodes) can filter by allele frequency. 

Click the "+" button to add more sliders for AF ranges (between 0 and 100%) you will allow through (AF in any of the slider ranges will be allowed through)

For nodes with multiple sample (Cohort and Trio nodes):

**all:** all samples must have AF within the range sliders

**any:** at least one sample has AF within the range sliders

![](images/allele_frequency.png)