 HaplotypeCaller: minPruning = depth / 500 rescues some false negatives https://github.com/broadinstitute/gatk/issues/3697 Update: There's more to it check here: 
HaplotypeCaller: minPruning = depth / 500 rescues some false negatives
broadinstitute/gatk#3697
Update:
There's more to it check here: